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Learn how to install a battery cut-off switch that kills the engine and all electrical power to-and-from the battery. I also show you how to crimp battery cables using a hand crimper, hammer crimper, and hydraulic crimper, so you will learn each method and how to get perfect crimps.
Jig Saw:
Impact Wrench:
Angle Grinder:
Heat Gun:
Kill Switch:
Small Wire Crimper:
Hammer Crimper:
Hand Crimper (and cable cutter):
Hydraulic Crimper:
Terminal End Kit:
2 Gauge (7mm) Wire:
Hole Mount Zip Ties:
Zip Tie Mounts:
How to Install a Kill Switch:
Parasitic Draw Test:
0:00 Intro
1:32 Tools and Products
5:40 Wiring Diagram
6:19 How a Kill Switch Works
11:20 How to Crimp Battery Cables
19:50 Easy Way to Add Split Wire Loom Tubing
20:29 Installing the Battery Cables
24:10 Organizing the Wiring
26:12 ECU Cut Off Wiring
31:54 Kill Switch Panel Fabrication
37:47 Panel Installation
39:20 Testing the Kill Switch
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Due to factors beyond the control of ChrisFix, I cannot guarantee against improper use or unauthorized modifications of this information. ChrisFix assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. Use this information at your own risk. ChrisFix recommends safe practices when working on vehicles and or with tools seen or implied in this video. Due to factors beyond the control of ChrisFix, no information contained in this video shall create any expressed or implied warranty or guarantee of any particular result. Any injury, damage, or loss that may result from improper use of these tools, equipment, or from the information contained in this video is the sole responsibility of the user and not ChrisFix.

Hey guys chris fix here and today, i'm going to show you how to install a battery, kill switch in your vehicle, and this is very important, so how this works is when you flip this switch. It completely isolates the alternator and the battery. So there's no electrical flow in the vehicle. It also kills that engine instantly.

So if you get into an accident, you have a fuel leak. You have an electrical short, you flip the switch and you can prevent a fire now if you already have a fire, when you flip the switch it'll prevent that fuel pump from running that way, it's not dumping fuel onto the fire, making it worse. So, as you can see, this is very important and today i'm going to show you how to properly install it. Now i know not.

Everybody has a track car, but there are other applications for a kill switch. For example. Maybe when you go to start your car in the morning your battery's dead, because something is drawing on the battery now i do have a video on how to find this parasitic, draw and i'll link that video in the description, because you should really be able to Find that draw and fix it, but for whatever reason, if you can't find what's causing that draw on your battery, a solution could be a kill switch. All you have to do is shut the switch off and then now your battery is isolated and won't drain.

Then, when you go back into the car to start it in the morning, you put it back on and your battery should be good to go. Your car should start right up and finally, if your car doesn't have a theft deterrent device, one way you could add one is with a kill switch. So when you leave the car you take, the kill switch out like that and now the car can't be started because there's no power. Now i do want you to remember anytime, you shut the kill, switch off.

You are taking battery power away from the computer away from your radio, so you're going to reset all those things. So just keep that in mind all right. So now you know the purpose of a kill switch. Let me show you how to install one and here all the tools and products you're going to need.

As always, i try to use common hand tools that way you can get the job done at home yourself, no problem at all. We're also gon na be using power tools because we need to make a bracket we're gon na have to fabricate something for our kill switch to mount to, and this is actually very important. Let me show you where this has to be mounted so tech inspection requires a track worker to be able to reach your kill switch from outside the car, so it can't be anywhere in the middle of the car it has to be over here somewhere, so they Could easily reach it in case of emergency, so the best spot is this right here. This is actually perfect.

You can see we have a nice cutout right here, that'll easily fit our switch and we can make a nice bracket this bracket right here is just a rough bracket. I made real quick just to mock things up, see how it fits the good bracket. The one we're going to fabricate in this video is going to fit in this area real nice. That way, it looks factory, race, car and one last important thing about this location.

Is our driver is able to reach this switch without taking the harness off? He could be completely strapped in and still kill the engine and electrical system. So this is the perfect switch location. So since we need to fabricate our own bracket to mount our switch to we're going to need a couple of power tools - and i do want to thank ryobi very much for sending me out some tools and supporting the video. They actually saw a previous video of mine where i used their da polisher and they reached out and asked what tools i could use.

So here's what we need. We need a drill, we need an impact gun, we need a heat gun and this heat gun is awesome. It has this adapter at the end for heat shrink, it works so well. I can't wait to show you that and then we need an angle grinder with a cut off wheel and that'll be able to cut the metal.

Now, i'm not here to try to sell you anything. I know some people have brands that they like to use. That's completely fine. I just thought this was very fitting to use on my channel.

My channel is all about fixing your car at home yourself diy. This is very diy friendly. Also, this is very budget friendly and one thing that i really like all these tools use one single battery type. This is an 18 volt lithium battery and they all work on this.

So you don't have to go and buy a bunch of different batteries and it saves you a ton of money. So those are the power tools that we need. We're also going to need some crimpers and i do have three different types. We have a hydraulic crimpers.

We have a hand crimpers and we have a hammer crimpers. You only need one of these, but i have all three to show you how they work that way, whichever one you have you'll be able to get the job done and then finally, we have our wiring supplies. We have heat shrink. We have terminal end connectors, butt connectors, and then we have our thick two gauge heavy duty wiring and we have our switch and our resistor, which comes with the switch, which is very important.

That way we don't damage the alternator when we flip that switch. So that's everything you're going to need i'll, be sure to link it all in the description. So you can easily find it. Let's get our safety glasses on and let's get started so first, let's pop the trunk and we need to disconnect the battery which in this car is located right over here.

So we want to disconnect the negative side of the battery, and this takes a 10 millimeter to loosen and then place that cable off to the side away from the negative battery post. So with our negative cable, disconnected our battery is completely isolated and the funny thing is our kill, switch, isn't going to be on the negative side. It has to be on the positive side, because that's the rules to pass tech, inspection for our race and also because we need to kill the alternator. We need to make sure we stop power from the alternator when we flip the switch off and that's on the positive side.

So what we need to do is we need to follow our positive wires. We have two here. We have one that comes up here and goes out to the front, and then we have the other one which comes over here and again out to the front. So let's go around and if you come to the rear passenger side, you can see we have both of our wires right here coming along passenger side door, sill right up there, and then we keep moving forward and we have our red wire here and our other Red wire here and that continues forward to the front passenger foot well right up here, so this red wire right here goes through the firewall and powers, the alternator and starter, and then this red wire right here goes with all these wires to our fuse box.

Under here, we're gon na have to end up cutting both of these wires, because we need to make sure that we cut power to our fuse box and power from our alternator to completely kill the car okay. So before we cut those wires any time you do any wiring on your car, i highly recommend drawing out a wiring diagram of what you need to do. It'll keep you organized and it'll, keep you from making any mistakes, so real, quick! Here's our wiring diagram, the battery's in the trunk and the two wires run up front to the fuse box and the alternator. Now we need to interrupt these wires with a switch, so we'll cut them right here and then we'll run the battery wires to the switch and then wires from the switch to the alternator and fuse box and that'll complete that circuit.

Now we're also gon na have to shut off the computer of the car, so we'll cut a wire at the computer and run it to the switch. And finally, our switch has to be grounded through a resistor. So we don't damage the alternator and i'll explain that in a second. So now you understand how the car is going to be wired.

That's very important. It's also very important to understand how the switch works and how you need to wire the switch so real, quick. Here's a wiring diagram for our switch. If you need this pause, the screen and screenshot it, but since i have a real switch, i want to show you how it works on this, so i have a multimeter set up that when you touch these two leads together.

It beeps and that's letting you know that the circuit is closed and there's electricity flowing when you take it apart, there's no more electrical flow, so it stops beeping. So first, let's look at the two main poles on our switch. We have the two battery wires going to one pole and our alternator and fuse box wires go into the other pole. So let's get the battery wires on one pole and the alternator and fuse box wires on the other pole, since our switch is off.

There is no electrical flow, but once we turn the switch on, you could hear clearly that we have electrical flow. So if we need to stop our flow of electricity, we just shut the switch off now. Unfortunately, this doesn't stop the engine from running. There's still electricity coming from the alternator and that's enough to keep the electrical system on the engine running.

So our switch has extra poles. You can see. We have four extra poles at the bottom here, labeled one and two. Let's start with number two here so circuit number two could go either to the ignition or the computer of the car.

So when you flip the switch, it kills the engine. So let's connect our car's computer wires to the number two poles on the switch. So when we turn our switch on, there is a connection to the computer. There's electrical flow so with the engine running.

If you want to kill everything, you flip the switch and now there's no electrical flow, so the engine will die within a second or two. Now, since it takes a second or two for that engine to die, it's still spinning and the alternator is still pumping out a little bit of electricity. But since we cut the circuit for the alternator, we need that electricity to go somewhere. Otherwise, the alternator will get damaged.

So that's where we need to use our number one posts. We're gon na have a jumper wire going from the alternator post down to the number one post. So when we flip the switch off, the current will go into our number one post on the other side and through our resistor to ground, so it dissipates that electricity. So let's connect our jumper wire from the main post to number one post and let's get the alternator wire on our main post and then let's get our resistor to ground on our other number one post.

So now our switch is on. So the electricity is going from the alternator to the battery, but once we flip the switch it's going to go down here to our jumper wire to our resistor and to ground. So we dissipate that electricity watch this. So it takes a couple seconds for that engine to die and our electricity is dissipated.

So it's very important that you guys understand that so now you know how to switch works. Now you know how we're wiring the car, let's go, cut some wires. So if we take a look at our wires over here, we have to decide where we're going to cut it. We could cut it back here.

We could cut it here. We could cut it more towards the front now. My fire suppression system is going to be right over here, so i'm not going to cut over here. I think it'd be a lot easier to cut the wires over near the front and then we could run our wires up behind the dash to our switch and from our switch down back over here now, when cutting your wires, it's very important.

We have a nice clean straight cut. We don't want to use small cutters like this, which you might have to hack at the wire and it won't cut straight so get a nice large cutters and again it's very important that we cut these nice and straight so. There's one straight cut and there's our other straight cut, so with our wires disconnected now. What we need to do is we need to run new wire from our two wires here to our switch.

So let's get the wire and run it up into the center console and then we want to pull this all the way through and then we can run it up behind the dash where the climate control and radio would be just like that, and you can see Already it reaches to where the switch will be. So, let's get the steering wheel out of the way to make some room. Now we can pull out the gauge cluster, which is still unscrewed from when the roll cage was installed and take a look at all the room back here to run our wires. This is perfect, so let's run this wire behind the gauge cluster like that, and then let's put the gauges back and there you go, our wire is run to where the switch is gon na be mounted all right.

That was perfect. We have a little bit extra wire sticking out here where our switch is going to be that's fine. I'd rather have a little bit extra than not enough, and then, if we push our gauges all the way back, that fits in perfect without touching the wire, which is good. We are going to put this wire in a plastic sheath.

That way, we don't have to worry about anything cutting into it and shorting out behind the dash, and then our wire runs down the center console and out to the side right over here now here's how much wire we have left there's about a foot of extra Wire, which is fine, we want a little bit of wiggle room. We could always trim this later, there's plenty of wire to get to these over here and there's plenty of wire to get back here, even to the firewall and at the firewall. Let me show you how this wire connects by removing this plastic cover. Okay, and you can see how it's connected to this post and i'm thinking, we could just remove this and run our wire directly to this spot on the firewall all right.

So, let's remove the wire that we just ran, because this is the perfect length and we could use this wire to cut our other three wires to the correct length as well. Okay, so let's spread this wire all the way out and then we have our bundle of new wire. So let's grab the end of the wire that we just ran and the end of the bundled wire and spread out this bundled wire. So it's the same exact length now this doesn't have to be perfect.

We could trim it later, but we want to get somewhat close, so we aren't wasting too much wire okay. So, let's cut this wire to length beautiful and now we have two of the same length wires and with some editing magic. Now all four of our wires are cut to length. So now we need to connect these wires to our switch.

Two are going to this pole. Two are going to that pole. That means we have four terminal end connectors that need to be crimped on. So let me show you how to crimp - and i have three different crimpers here - that i'm going to show you how to use a hammer, crimper a hand crimper and a hydraulic crimper.

They all work, but they have different price points and there's also some pros and cons of each but whatever you have i'll make sure you guys know how to properly crimp it and get a great crimp. Now, no matter which crimper you use. You need to make sure that you splice the end of your wire properly and also pick out the proper crimp. So let me show you real quick now when picking out the proper crimp you can see on the crimp.

There are two numbers, two by three eighths, so the two is which gauge wire fits in your terminal end connector. We have a two gauge wire, so we pick a two gauge terminal and connector, and the 3 8 is the size of the hole so the size of the stud that this fits on. So if we look here that fits perfectly on this 3 8 stud, so we have the correct terminal and connector once you find the correct connector now we need to splice the end of our wire. Now remember, i said it's very important for this to be straight.

Do not cut your wire at an angle. You'll see why, in a second now how i like to splice thick battery cable like this, is with a razor now when splicing your wire, it's very important. You just cut through the outside insulation, do not cut into the copper if you cut off any of these copper strands, that's not good! So what i like to do is i like to get my terminal end connector and i like to match it up like that, and we have a really sharp razor and we just stick it straight into the insulation. Do not saw so now.

We know where we need to cut. You don't want to saw back and forth because that'll cut into the copper and you'll lose some strands, so instead just use pressure straight down. Then you can work your way all the way around pushing downwards, making a complete circle around that wire and then finally make a cut perpendicular to that again, just pushing straight down, and now the installation comes right off and look at that we didn't lose any copper Strands at all now, the reason why emphasis not losing any of these strands not cutting into them and breaking them off, is because think of each one of these strands as a water hose, and you want the maximum flow of water. If you cut a bunch of hoses off you're going to have less flow of water same thing with electricity, the less copper there is the less of these strands, the less flow of electricity this could handle.

So we don't want to lose any strands all right now before we add our terminal and connector. I always forget to do this, so i want you guys to remember always add your heat shrink now. This is very important because, once the terminal end connector is on there, our heat shrink is a little bit too small and won't fit so add your heat shrink and push it all the way down the wire. Now we could add our terminal end connector and when adding the connector it's important, we get all the strands inside the connector.

We don't want to get any outside the connector like that. That's not good! So what i like to do is twist and pinch the wires at the end and that keeps them nice and tight. And then, when you add the terminal, end connector just twist and push it on and you want the connector to push all the way to the wire insulation like that, and now the wire is ready to be crimped. Okay.

So let me show you how the hammer crimper works just get the middle of the connector into the crimper like so, and then you want to grab a hammer, i'm using a four pound hammer and hammer the top of the crimper until it bottoms out, and you Could feel and hear the difference, so that's three hits and it's bottomed out completely, which means it's fully crimped. So let's check it out and that looks pretty good. So that's how you properly use a hammer crimp, but now how do you test this crimp to make sure it's good? Well always do the pull test. This should feel solid, and this is not budging anywhere.

But how do we know inside this? Crimp is solid. There's good conductivity! Well, there's a reason why i told you you always should do test crimps and that's because you want to cut this in half and look inside now to give you an idea of what a good crimp looks like here's, a factory oem crimped battery cable from a Bmw and if you cut it in half you can see this is completely solid inside. There are no individual strands of copper, visible, they're, all compressed into one solid piece of copper and there's no air gaps. So that's a good crimp! That's going to conduct electricity well and then for an example of a bad crimp.

Here you go, you can see the difference right away. You could actually see the individual strands of copper and there's air gaps, so this is a bad crimp and this won't conduct electricity. Well so now, let's see how the hammer crimp turned out and to do that, let's saw the crimp in half right down the middle and look at both sides of the cut all right. So, with our terminal end that was hammer crimped together, you could see we have absolutely no individual strands.

That is one piece and that looks absolutely perfect. So that's how you use the hammer crimp to get a perfect crimp, and this is probably the least expensive crimper. You could get for thick cable now the downside is, you need to have a solid foundation to hammer on, because you really need to hit this real hard. Also, you need to swing a hammer.

So if you need to do this inside the car or on a soft surface, you won't be able to use this crimper. So next up is our hand crimpers. This is a little bit more expensive than a hammer crimper, but cheaper than our hydraulic crimper, and it gets the job done. Let me show you how it works.

This right here is: what does the crimping and you can see - there's dies here so you're actually able to switch the dies, which i thought was really nice, just a press of a button like that. You flip them over and they lock in place and you could go from eight gauge all the way down to zero gauge. Now, a downside to the hand crimpers is the die, isn't very wide. So it's going to crimp in a small area, so we could actually probably crimp right there and then crimp again right there.

So, let's start near the base. Now, when crimping, you could use two hands to grab the crimpers and squeeze, but that's a little difficult, especially because this could pop out like that by accident. Now what i like to do is i like to brace the tool against the toolbox or the floor wherever you're working with one hand, you could grab this. With the other hand, you could grab onto the wire and hold it in place as you crimp.

So squeeze the crimper closed good and you can see we just crimped up here. So let's slide it down a little and repeat so squeeze one more time and look at that. We got both of our crimps on there. So it's a nice big area, that's been crimped and compressed, and that looks perfect.

Now, let's cut our hand crimp in half and see how we did so, here's our crimp and here's what it looks like inside and you can see it's one solid piece of copper all the way through. So this is a good crimp and finally, we have our hydraulic crimpers. Now these work absolutely amazing, but they are the most expensive of the three. So if you don't need to use it often or you're, only gon na have to use it for like one or two projects.

It might not be worth it, but you get perfect crimps every single time. So let me show you how it works. Now. This crimper will crimp from 12 gauge wire all the way up to 20 gauge wire and for our two gauge wire, here's, the crimps that we're going to need.

So each of these dies fits into the crimper like so, and you want to line up your connector in the middle like this, and you can see how wide this crimp die is, and this is going to give us a bigger crimp, which is good so just Pump the crimper handle just like you would a jack and the hydraulic power will crimp the connector effortlessly perfect and let's remove the crimp and that's looking pretty good. But let's make sure so you know the drill by now: let's cut the crimp in half and let's check it out. Okay, so this is actually not good. I mean it's not horrible, but you can see, there's still strands of copper, which means we need to use a smaller die.

So, let's try this again this time using a die, that's one size, smaller, so crimp down on the fresh connector, and then let's saw this in half, so we can see the results, and this is much better. You could see it's one solid piece of copper. Compare that to before, which has strands visible, and now you can see why it's always good to do at least one crimp test when crimping thick gauge wire like this and now you know how to use all three different crimpers to get perfect crimps. This one isn't going to work in our car because we can't hammer against the floorboard and this one's pretty expensive.

So i feel, like most of you are going to end up using this, which is what i'm going to use to do this entire job. So now we know how to properly crimp, let's crimp four of these terminal ends one on each end of the wire. All right so remember, line up your connector and cut into the wire insulation to mark. It then cut all the way around the wire like so and then cut along the wire to easily remove the insulation without damaging the copper strands.

Now you want to pinch and twist the strands and then add the connector to the end of the wire pushing it all the way on and finally make your first crimp good, followed by a second crimp good, all right. So all four wires are crimped perfectly and now you guys know how to properly crimp with three different tools. Now you always want to look over your crimps, because you can see right here. We have a few sharp burs from the crimping process, which isn't good so to remove these burrs just get a file and file them smooth.

The burrs need to be removed, so the heat shrink doesn't get cut when it shrinks down on the copper and that's much better. Okay, great now, all these are nice and smooth. So, let's add our heat shrink and a little trick i like to use is to grab some silicone paste and add it to where the connector and wire insulation meet this prevents moisture from getting in and causing corrosion now. Is it overkill to do this? Maybe, but you guys know i like to do everything to perfection, and this is perfection now we can add our heat shrink, so it covers the connector like that, and we want to do this for all four of our wires all right and i can't wait to Show you how this works.

This is one of my favorite tools, so let's connect the battery to the heat gun and we have an adapter here that goes right over the end, for our heat shrink now watch this just put the heat shrink in here: pull the trigger and this works so Well, to heat the entire heat shrink, we don't even have to twist the wire just run it through and watch that heat shrink shrink down and push out any excess silicone to make a watertight seal and again do this for all four wires. So with that done now, all we need to do is add some sheathing to our wires and you guys probably already know how to do this. You slip the split tubing over the end of the wire and push it down the entire wire. This is a very tedious and hand cramping job, but do i have a trick to make your life easier, so you want to grab a wrench like this, and you want to slide that closed end of the wrench over the wire then slip the wrench into the Sheathing and run the wrench all the way down the length of the wire.

This definitely works a lot better when the wire is thinner or the sheathing is thicker, but even in this tight situation it still gets the job done. So you can see how much quicker this is and how much easier it is on your hands. So hopefully this little trick helps all right. So our wires are completely done.

They're crimped, they're, heat shrinked and they're protected. So let's go install them in the car. Okay. So before we go and install our cables, we have a very important step.

We need to mark the cables you can see. These are just red. At the end, these are going to our battery. I put a little bit of yellow tape on the ends of these cables.

That way, i know where these are going. Otherwise, i'll have no clue because it's going to be hidden behind the dash so trying to trace this you'll have to use a multimeter. It just wouldn't be fun so mark it now and save some time for later. Okay, so time to run all four of these wires up to the switch the same way.

We did before so push them up through the console and it's tight up here so we're gon na pull two wires at a time to the top of the console, and then we can get those other two wires up here as well, and then we can pop The gauge cluster out and run the wires behind the gauges and luckily there's a lot of room back here because there's four of these two gauge wires, which ends up using a lot of space and let's push the gauges in and see if they still fit. And they do perfect and finally, we could get the wires to where the switch is going to be, and so you guys remember, we have the battery cable on this side of the switch and the alternator and fuse box on that side of the switch along with A jumper wire that we have to install so let's get the alternator and fuse box wires on and you can see how marking them with yellow tape just makes it that much easier to identify them. Then we can get our jumper wire on here and finally, we need to get the split washer on and start threading on the nut, but only hand tighten it for now, we'll tighten it all the way later on the other post get both of our battery wires. On here, then, we want to get that split, washer on and then hand tighten the nut to hold it all in place.

Good and let's get it into position like so, and we will make a bracket. So this switch fits nicely in over here, but we want to finish wiring this up because that's the priority, the bracket's, the last thing we're going to do - and this is the perfect example of why marking the cables was important. You can see here's our alternator and fuse box cable and here are our battery cables. So let's separate them and we'll start up here by removing the old alternator cable.

So let's remove this nut and the cable comes right off. So now, let's get the terminal end. Crimped onto our cable here and i'm changing it up using a hydraulic crimper to speed up the process and it makes a large single crimp, which makes this easier then add some silicone heat shrink the connector on and push the sheathing back onto the wire. All the way at the end and then use some electrical tape to hold the sheathing in place at the end of that wire.

Now, let's connect our new wire to the firewall hand, tighten that nut on there and then tighten it the rest of the way. So it makes a good connection and finally, put the plastic cover back on all right. So with the alternator wire completed, let's get the fuse box wire done now for this we're using a butt connector to connect the two wires together end to end so just push the connector onto the end of the wire. So it goes to the middle of the connector and then crimp down on that wire good, and now that half the butt connector is crimped.

You can't forget about your heat shrink, because if you don't add it now, there's no way to put it on then slide. The other end of the butt connector over the wire and crimp down nice and tight to make a solid connection. Then we could add some silicone paste and use a heat gun to shrink. The heat shrink just like that and that's how you connect two wires with a butt connector.

Okay, now the fuse box and alternator wires are done. So, let's finish up with these two battery wires, so crimp down on the butt connector on one end, then slide it over the other wire. We want to connect to and crimp that down as well. Add your silicone paste and then heat the heat shrink to insulate the connector.

Then the last thing to do is get a little bit of plastic sheathing onto the wire just so you have some extra protection and with that done, let's move on to our last wire and i think you get it by now. Crimp, the one end on connect the other wire and crimp that end on as well. That way, you have a solid connection. Then you add the silicone paste heat up, that heat shrink to insulate the connector and finally add that plastic sheathing for extra protection and just like that, we are done with our main wires.

They are all crimped. They look good to go and well they don't look that great. They look like spaghetti right now. We need to get this organized for both safety, so we pass tech and we don't have these things flying around as we're racing and also for aesthetics.

We want to look good too, so for our first wire up front here. They make these zip tie mounts that stick on with double-sided tape, and this will help us organize our cable. Now everything we've done so far to crimp and wire. This car has been done to an above and beyond standard in order to finish this job properly.

It's important to have a good wire management that not only looks good but keeps the wires in place so in case of an accident, the wires don't get damaged. So, let's route this wire along the floor then clean the painted surface with some alcohol, so the double-sided tape sticks. Then we can remove the backing on the tape and press that zip tie. Mount firmly in place now run the zip tie through the mount put the wire over the zip tie and zip tie that wire in place like so and don't forget to clip the end of the zip tie like that, then, let's repeat this process, one more time Right here and get that cable, zip tied in place beautiful, so our alternator wire is neat and secured.

Now, let's get these wires neat and secured, and to do that, i have this really large one-inch wire sheath. So, let's tuck that first cable in here good and let's get these other two cables in here and it's going to be a tight fit, but we can make it work with a little finessing good now to hold this in place. I have a zip tie that pushes into the hole in the metal - it's like one of those christmas tree panel, clips that hold the plastic panels in your car and just to give you a better look at this. These zip ties are awesome.

They push right into the hole, that's already in the metal and then you can zip tie the cables down. So it secures it right to that piece of metal in the car and don't forget to trim the end of the zip tie and the other zip tie. As well all right and check it out, that's not going anywhere that looks so good and all our wires are now secured. Now we just need to clean up the wires up here, because this is a mess and also our wires back here.

So, with a little bit of editing, magic check it out and one more time, beautiful all right and what a huge difference a little bit of wire management makes. Not only does it look absolutely amazing, nice and organized, but it's all protected. That way in case of an accident, none of the wires will be exposed, they can't short and we are good to go. That is a professional job right there look at that.

I love it. Okay, so now you know how to crimp. We got the main wires done next up, we got ta, get our ecu wires wired to the switch all right, so we just finished wiring in our four main wires to our switch. Now we have to do the ecu and the ground, and now the ecu is the car's computer.

It's also known as the dme in a bmw and it's located right over here underneath this plastic cover. So, let's remove the cover and one of these wires has to get cut but which one so to figure that out i printed out a diagram of our relay box. You can see number one is our main computer number four. Is our computer main relay that relay provides power to the computer? So if we cut out that relay it can't provide power and our car will shut off instantly and when you compare to the diagram you can see, our computer is right back here and our main relay is this blue one right here and unfortunately this won't come Out unless if we take the wires off the computer, so let's remove the wires from the computer and don't worry these wires only fit in one position.

So you can't mix these up now with the ecu wires out of the way we can pull this bracket out and get access to the wires below the blue relay. So if we take a look at our relay here, you can see there's three thick wires. These are the power wires, there's a lot of current going through these wires, and then we have one thin wire right here. This is a trigger wire.

There's not a lot of current going through here, a little bit of current goes through and that triggers the relay to turn on and power the ecu with these wires. So this is the wire we want to cut and just to make sure before we go and cut it. Let's start the car and disconnect this and see if the engine shuts off now in order to get the car to start, we need to reconnect our battery, but before we even do that, we need to reconnect our ecu, so here's the ecu and, let's plug all These connectors back in and can't forget about this connector back here. Okay, so everything is reconnected.

Now we can connect the battery, but before we connect the battery real quick because we don't have this switch mounted yet the back of the switch is exposed. We just want to make sure it's dangling there and not rubbing up against any metal, so that is just dangling there. It's not touching any metal. So now, let's go to the back of the car and reconnect our battery and i'm just going to slide this on and not tighten it down because it's coming right off after this test.

Okay in the car, let's go starter up so with the engine running. Let's pull this wire out and make sure it's the correct one beautiful and that kills the engine right away. Now, let's disconnect the battery again, so we're not working on a hot car and then let's reconnect the wire to the relay. Until you hear a nice, solid click good and now we can cut our wire and strip each end of it and with the wire cut now, what we want to do is run each end of the wire to the switch.

So when the switch is on, there's a complete connection and the engine will run and when we shut the switch, it interrupts that connection basically like cutting it and the engine dies instantly. So, let's add a butt connector to the wire. We just cut and crimp that on there nice and tight and always do the pull test to make sure your crimp is good. Next, we could add a length of wire that will reach our switch.

So, let's crimp this on as well and then heat shrink it down for a corrosion, free connection and real quick. Let's do the same thing for the other side of the cut wire crimp it down, get another length of wire that goes to the switch and crimp that down as well and with these crimped heat shrink, the butt connector and, let's tape this to the surrounding wires. So there's no pressure on our newly crimped wires and it stays in place now, let's disconnect the ecu. So we can get it out of our way and then grab our two wires and run them down here through this hole back here, and this goes right into the car and let me show you okay, so if we come right down here by the pedals, you Can see the wires are coming through so pull these all the way through, so that they can reach the switch.

And now we need to crimp on female blade connectors to the end of both of our wires. Like so, and then heat shrink them down and it doesn't matter which wire gets connected to which spot just make sure they're both securely pushed onto the number two poles and finally connect the jumper wire to the number one pole, and that leaves one last pole right Here so with these wires connected, it's very important that we protect the wires, so they don't chafe and rub up against a sharp piece of metal in the car and kill the engine. So you know the drill by now slide on a piece of plastic wire loom like this, so the wires are completely protected. Alright, so with that done, we have to finish wiring up this last spot right here.

So all we need to do is connect a wire like this to a bare piece of grounded metal and we need to make sure that we add the included resistor in line. So let me show you how okay, so, let's cut the ground wires. So we can add the resistor in line then strip both ends of the wire slide, a butt connector over the resistor and crimp down now crimp the wire onto the resistor good and crimp, the other wire onto the other side of the resistor good. Now heat shrink down both connectors and, let's add heat shrink over the resistor, so slide one piece of heat shrink over the resistor and shrink it down then slide the other heat shrink over the other end and shrink that down that way, we're covering the entire resistor And finally, get some plastic sheathing over the wires and tape up the resistor, so it doesn't come out of the sheathing good.

Now, let's get this installed so one end, we need to connect to our switch, and now we have to find a ground to connect to - and i like this bolt right here - it goes into the chassis, it's on this big piece of metal and it's bare metal. So, let's remove the bolt, then get the ring terminal on the bolt and tighten that bolt back down by hand and then snug it up the rest of the way. So it makes a good electrical contact so with our ground bolted in. All that we have left is to make a mounting bracket for our switch, we'll do that in a second, but first real quick.

We need to come over here and reinstall all of this. So, let's secure the relays back down in its container like that, then we can install the computer, and now we have to attach all the wires and each set of wires has a specific plug shape, so it only plugs into one spot on the ecu. So you can't mix it up, just make sure you push the wires all the way down, so they snap in place and then we can get the lid back on and snug up the screw holding it in good and with our ecu all sealed up. We've officially wired in our kill, switch now before we go and test out this kill switch.

We need to make a panel for this to mount to, so it's not just dangling here. So let me show you how we're going to do that, and here are all the tools you're going to need now. Originally, i was gon na use a cut off wheel on an angle grinder to cut our aluminum sheet, but i think it's gon na be a lot easier to use a jigsaw, so i went out and got a jigsaw with a metal cutting bit. That way.

We could cut into our eighth inch aluminum sheet no problem now i like to use either cardboard or in this case card stock, to make a template before we cut into our sheet metal. So let me show you how so card stock's nice, because it's thick enough, but it's thinner than cardboard so it's flexible and makes it easy to trace shapes on. So now, let's cut this out and just like that we have our template so now get the template over the metal we're using for the bracket and trace out the entire template with a thick marker. That way, we could easily see where we need to cut now.

It's time to use our jigsaw and you can see it's on the slowest setting and for aluminum it's better to increase the speed a little bit. So it keeps the teeth from clogging up with metal and now we're ready to cut, and i think you're going to quickly realize why i went with a jigsaw here. Instead of a cut off wheel. This tool is so easy to use and cuts right through the metal like a hot knife through butter.

Also, the cuts are much quicker and more accurate and much cleaner, so cut along the black line. We just traced out - and let's start shaving this piece down to size all right and now we have our bracket cut out. So let's see how it fits in the car okay moment of truth, let's test fit our panel and wow, that's actually pretty good. We do have to trim up here a little bit around that corner.

We have to round this corner right here and this corner and that corner okay. So let me show you how we're gon na go around these corners so to get rid of these sharp corners and make it fit better. We're gon na use a metal file, so there's no exact science to this just file down the corner and keep that file. Moving, so you don't remove too much material in one spot, perfect, so repeat this process on the other corners and get them nice and rounded, so they fit in the dash better.

All alright, let's test fit this again after smoothing out those corners. Okay! So now that these corners fit very nicely, let me show you how to smooth and round these edges that way. This fits and looks even better, so grab 180 grit, sandpaper and curl it around the edge you want around and just move it back and forth like this, and after a little bit of sanding check it out a nice, rounded edge. So repeat this process on all the edges of the bracket.

That way, you get a way more finished and professional. Look so with all our edges, rounded and smooth. Let's go give this another test fit and see how we did here. Okay and i'd say that's pretty good, especially for a race car.

Now, let's drill our holes for our switch, we'll have two holes up here for our fire suppression system and then we'll need some holes to mount the bracket to the dash. Here you can see, we have two good mounting points. These bolt holes right here, that's how we can mount our bracket so get your template in place and to figure out where the holes are. All you need to do is press your template, hard against the holes and, if you use the rounded end of the screwdriver, you can make a pretty distinct outline of the hole like that.

So do the other side as well, and let's drill out these holes. Okay, so take the template and place it over our bracket and then use a center punch to mark where we need to drill, and then we could drill out both the holes and that's one hole, and then we could drill out the other hole good. So with both holes drilled, let's go test fit this in the car and let's thread in a bolt on this side. Good and let's try threading in the other side as well good, so both sides threaded in straight and now our bracket is secured in place.

All right so now, let's unscrew this and get it out of the way, because we need to make a template to cut the switch holes out. So the main hole is a 7 8 inch hole. But we need to get the location of the smaller holes that mount the switch to the bracket. So let's get this on here and then use the back of the screwdriver to make indents in our cardstock and that's where the holes will go now, let's get the bracket back in and then tape up both sides of the template where we want the switch to Be good now, let's go and cut the holes, so first center punch the main hole for the switch, and since we need to drill a large 7 8 inch hole, let's use a step drill bit and a helpful trick to know when to stop drilling is to Mark the bit with a bright color like this green right on the 7 8 inch step.

So once this color disappears, you know you're done drilling so get the bit centered on that center punch, hole and start drilling with this bit. You want to apply firm pressure downwards until you get a hole after you drill through now. You can apply lighter pressure and let the drill do all the work. Okay, so the metal is scraping off as we drill and it's messing up the template so before we destroy it.

Let's mark our two smaller holes with our center punch and now we don't need this template anymore. So, let's finish drilling our main hole and watch how easy it is to tell when to stop drilling boom, no more green, so we are done and finally drill out the two smaller holes for the bolts to hold the switch in good all right now. Let's make sure our switch fits to get the screws in place and beautiful, so our switch bolts in perfectly that looks good and there's a big space up here, for whatever you need more switches. In this case, i'm going to be installing two fire suppression system pull switches and, if you're wondering what they look like, these are the two pull switches: that'll set off the fire suppression system in case of a fire.

So, let's drill out those holes. Now these holes have to be a half an inch wide and that's one, and then let's put the second one slightly below that that way, it's out of the way of our kill, switch good and there you go. That is what it looks like with the switches in place. That looks so good.

So now, let's sand this down and paint it so use some 320 grit sandpaper, and you want to sand down all the scratches and gouges out of the surface. Anything you see now will definitely be visible after you paint so sand. This nice and smooth then get some 90 alcohol and wipe off all the dust and any oils for a fresh, clean surface to paint after letting this dry for 10 minutes. Let's paint now the paint i'm using bonds straight to metal with no primer needed, then, after a few minutes spray one more coat, the same exact way for a total of two coats and now we'll let this dry overnight and a day later check it out.

This came out awesome, so let's get this installed. First, let's get the mounting bolts in and i'm screwing this in slowly. So i don't damage any threads. Then we can get the other mounting bolt in as well good.

Now we can get the kill, switch in place and then push both bolts into the switch to hold it in, and the nuts i'm using have a lock washer built in which makes this quick and easy so just hand tighten the nut onto the bolt and then Tighten it down the rest of the way until it's snug same for the top one, just tighten it down until it's snug and since this is plastic, make sure you don't over, tighten it because you could crack it. Finally, let's get our fire suppression switches in so carefully feed the switch all the way in and then hand tighten the nut on the back of that pole switch and do the same thing with the other fire suppression switch feed. It all the way in just like that and then hand tighten the nut on the back. Finally, let's snug the nut up with a wrench, so it won't budge and do the same for the bottom one as well.

Now the last thing to do is tighten down the two main nuts on the back of the switch all the way, so they make good electrical contact and won't come loose. I waited to the end to do this, so the cables could move around on the pole, because the cables are thick and stiff. It makes it a lot easier to move the switch around when you're trying to install it and now one last thing i added these silicone post covers, and these are pretty important. They go over the two positive posts like that, and this will prevent anything grounded from touching this by accident, which would short it out and could cause sparks.

Okay - and the last thing to do is to get the negative terminal back on the battery and tighten it down, so it's snug, and now our battery is hot all right. So, with our battery connected moment of truth, let's go and test out our new kill switch. All right, let's try it out, let's turn the switch on and we have power okay clutch in: let's try starting her up. Okay, she's alive, that's a good thing all right, so i let the engine idle for a few minutes and she's running perfectly.

Also, when you rev it up, she has plenty of power now at the race in order to pass tech, inspection and get on the track. We need to be able to rev our engine over 3000 rpms and hold it there and then the tech inspector is going to flick the switch off and make sure the engine dies quickly. So, let's give it a try: let's get our rpms above 3000 rpms hold it steady all right! Now, that's what i'm talking about. We had the engine above 3000 rpms, we flipped the switch and it killed everything instantly and we have no power at all.

So now we know we properly installed our kill switch and one last thing to do is to put our kill switch sticker on here. So the track workers know this is a switch that kills the power and now we've officially finished, installing our battery cut off switch. So our mounting bracket came out awesome, our fire suppression switches came out great and, most importantly, our battery cutoff switch works perfectly. So that's everything you need to know on how to install a kill switch.

Hopefully, this video was helpful if it was remember to give it a thumbs up. If you're not a subscriber consider hitting that subscribe button, we got some more videos coming up and, as always all the tools and products i used in this video will be linked down in the description, so you can easily find them.

12 thoughts on “How to install a battery kill switch”
  1. Avataaar/Circle Created with python_avatars Deepak Menon says:

    Oh nice! Another video. I couldn't really tell what it was from the ig stories. I finally know now.

  2. Avataaar/Circle Created with python_avatars JJ G says:

    could someone give this man an award please. Much appreciate your time and effort Chris


    from Toronto, Canada

  3. Avataaar/Circle Created with python_avatars Eli says:

    Hey chris!!!! I just wanna say you're a huge inspiration to me and I've loved cars and racecars since I could talk and I've been watching you for like 6 years and I've rewatched all your videos 10 times and I just wanted to tell you I got accepted into UTI Orlando for automotive technology and I'm doing the bmw specific program:)))))

  4. Avataaar/Circle Created with python_avatars Random Guy says:

    i wonder if hes ever not going to end this series and when is he getting more hp on the driftstang??????

  5. Avataaar/Circle Created with python_avatars Luscious Lunk says:

    My 4.0 01 Ranger has a battery bleed issue, I reaLly gotta do this or check out your other vid!

  6. Avataaar/Circle Created with python_avatars Simon plays games says:

    Can't wait to see the video of the race since I can't compete in the race myself I'll have to live through you

  7. Avataaar/Circle Created with python_avatars Dustin Bergeron says:

    I definitely love ryobi products. It’s way cheaper than brands like Dewalt and it’s more reliable than brands like Milwaukee. I work as an electrician and when I started we had 3 drills on the job trying to do our rough in all 3 of the chucks stripped out because of poor design I went go grab my ryobi drill and did the whole house with 1 drill

  8. Avataaar/Circle Created with python_avatars Oxygon says:

    I installed one of these like this and my engine starting running bad and the mechanic said todays cars need to stay in constant contact with battery power… They are designed for it. You can fry the computer with this type of on/off switch.

  9. Avataaar/Circle Created with python_avatars Barry O'Neill - The Pace Factory says:

    Well done you made a video on something every motorsports person has been doing since we were teenagers 👏🤣💯

  10. Avataaar/Circle Created with python_avatars Dezha Quinn says:

    Is it okay for the computer to use a kill switch every day for anti theft? I'm currently researching all the options there are for keeping cars safe against theft. Someone told me taking out the battery will "mash up" the computer so I thought an option like this would be out. This video is in such good timing because I was just thinking about something like this. Can you make a dedicated video about the best ways to prevent auto theft? Please and thanks

  11. Avataaar/Circle Created with python_avatars VeLocity says:

    I was checking your channel for a new upload and finally got one by the way I love the videos :>

  12. Avataaar/Circle Created with python_avatars Vyn Solina says:

    Can't wait to see how this car turns out! And the video quality is getting better than ever!

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