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Roadmaster Stop Light Switch Kit Installation - 2018 Jeep JL Wrangler Unlimited

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How to Install a Roadmaster Stop Light Switch Kit on a 2018 Jeep Jl Wrangler Unlimited Rm 751490

Speaker 1: Today on our 2018 Jeep Wrangler JL unlimited, we're going to be taking a look at the Road Master Stop Light Switch Kit part number RM-751490. So here's what our stop light switch looks like once we have it installed on our Jeep. I had this panel removed underneath the steering wheel so we can see a little bit better. Now the purpose of this kit is because we are going to be flat towing our Jeep and our supplemental braking system has an indicator light. Now the way our Jeep is wired up it has a retained power for the accessories which means that our brake signal and the factory brake switch will work for a few minutes when the key if off but after a few minutes it goes dead and then we won't have a signal to send out to our monitor light.With our stop light switch we're going to get a true reading of our brake pedal arm movement rather than just that power wire. So whether our supplemental braking system is pushing on the brake applying it, or if something we're to fall onto our brake and apply them, that is going to send a signal to our monitor so we know exactly what is going on.It is going to be a pretty straightforward installation.

We're going to have this bracket that we're going to have to put in place and then put our switch in and make a few adjustments. So let's show you how to do that now. To begin our installation we're going to remove this panel here. Now it should just pop out, but if you're having a little bit of trouble you can take a plastic trim panel tool and you're just going to go along the edge here and you're going to pull this panel directly out. There's just clips holding it place, and work our way around un-clipping them.

Then we're going to set this aside. With that panel removed, we find the steering column here, we look just to the left of it, there's going to be a bolt we're going to have to remove. You want to grab a 13 mm socket and coming from the bottom just kind of feed it up, it usually helps to use a long extension. Then we're going to remove the nut that's right there.So we can grab our bracket and the stop light switch. Now the switch is going to have two nights and an start washer on it.

We're going to want to remove that outer nut as well as the start washer. And on the bracket it's going to be extremely hard to see, but one hole is just slightly bigger and if you try to put the stop light switch in, it won't fit. So we're going to use the larger one where it should just slide in pretty easily, and for now, we're just going to adjust this nut so it sits about half way and then loosely put the start washer and the other nut in place. We don't want it super tight right now, we just want it tight enough that it's not going to be moving around too much on it. Then we're going to take our bracket and we're going to slide it over that stud and secure it with the nut that we removed.

Just get it on there hand tight for now. And you can see that our switch is going to hit this plate here that's connected to the brake arm.So we can hold our switch in position, make sure it's lined up properly and we'll tighten down that nut. With our bracket and stop light loosely in place, we're going to start making our electrical connections. Now on the back we're going to have two black wires. We're going to need to strip back the ends of each one. One of them, we're going to take one of our wires that comes from our Invisa Brake Kit, and one end's going have this connector on it and the other end is just going to be a bare wire. We're going to strip back the bare end and use a butt connector to connect it to one of the wires on our switch. Now it doesn't matter which wire we go to, just want to make sure you have a good connection and that you get your butt connector all the way one.With our one wire connected, on the other wire we're going to take the included red wire in our kit. We're going to strip back one end and crimp on another butt connector and connect it to the other wire switch. Easier to come through this hole here to connect it, but just make sure to route the wire back down through the back side so that we don't have that wire sticking out the front. We're going to route our wire through the back side. Now both the red wire and our monger light wire is going to have to go into the engine bay.So we use the same grommet that we used for all of our other wiring, just to the left hand side, over by the firewall. Once we have most of our wire pushed through or a little bit, we'll move into the engine bay and pull all the excess out. Now you want to be careful not to pull too tight and it's not a bad idea to go inside and double check and make sure the wires didn't get hung up on anything.We're going to start with our red wire. This is going to be the one supplying power to our switch. So we're just going to route it along the same way towards the passenger side where are battery and fuse holders are in place. Go behind these brackets and go towards the passenger side. So we routed our wire over towards our fuse box and our battery on the passenger side. Now if we lift up and push on these two tabs on the fuse box we can remove the cover. Now the way we normally would supply power to our brake switch would be through a fuse tap. But if you can see, our fuse tap is made for a mini fuse, where our Jeep doesn't have those, so it wouldn't even fit in the spot to put in. So instead we're going to be using a fuse holder as well as the provided 10 amp fuse that comes with our kit and we're going to be going directly to the battery so that way it's still fuse protected, and we can get everything in line.So we're going to strip back the end of the wire that we ran from the inside, we're going to take a butt connector and crimp it on. Then we can take our fuse holder and each end is just going to have a little bit of insulation that's already stripped back so we'll take it off and we'll slide it in to our butt connector and crimp it in place. So now we can just kind of loosely route our wire to make sure we're going to have enough room. We can lift up the cover on our battery and we're going to be going right to the positive post. So we're going to need to grab a 13 mm socket and remove the nut. So we'll loosen that nut up and we're going to need to put a ring terminal in place before we can put our wire on.So we'll slide our ring terminal over and crimp it in place. Now the ring terminal does not come with the kit. We can remove the nut. If there's any other terminals on the battery you want to make sure to put those back before we put the nut back in place. With our connections made, we can take our 10 amp fuse, slide it into the fuse holder and we just take a couple zip ties and secure our wires and make sure they aren't loose underneath the engine here.Our black wire, we're going to run down the same way we ran our four pole wiring and we're going to route this black wire up to the front by our electrical connector. Again you just want to be careful because there's a lot of heat sources and moving parts up here. So you just want to make sure that once you route it you secure it with a bunch of zip ties, making sure it's not going to get damaged. So I routed that wire up to where my electrical connector is. Now we've got a couple different options of what can do here. We can tie up the excess behind our skid plate to where we're only going to have a little bit of that connector sticking out and then you would take the patch cord and would plug into the connector and the other end would go into the motor home side.However, we're going to wire ours directly into our six way connector. That way it's a little bit more permanent and we won't have to worry about any kind of moisture or corrosion or anything happening to our wire. Not to mention we don't have to worry about losing our patch cord. So we'll just take our connector off, and ours is held on by two 5/16" self tapping screws, so we'll pull those out and you want a little bit of room, so we'll pull our connector out just a bit, we're going to pull the dust cover off. We're not going to need all of this wire, so we're going to give ourselves, more than we need, but just enough to work with. We'll cut our wire and then we're going to take the end of it and pass it through our dust cover and once we have it through, pull the excess out, slide the dust cover back.Now we're going to be wiring ours into the brake signal. That way whenever the brakes are pressed it will send a signal to our six way and then to our motor home. Strip back the end of our wire, then we can take a small screwdriver, we're going to need to find the terminal that's labeled S on the back of here. So we'll loosen it up and then we can take our wire, put it into the terminal, now you just want to leave a little bit of that copper out the very top because you don't want the insulation to get stuck in there and cause kind of some connection issues. Push the excess wire out the back, and then we can put our dust cover back on.Now you suggest that you tie up any excess wires behind the skid plate and we won't have to worry about them. To make sure we're not going to get any moisture or anything else inside of our connector, we're just going to take a little bit of silicone, we're going to fill up the back hole here, we're all the wires are going in, so we have a nice secure connection point, we don't have to worry about any kind of corrosion building up. Then on the front end, we're just going to take some tape and wrap it around until we get it back towards that silicone. Push your wires back in place, line up the connector and replace those two screws that we're holding it in.With our wires ran and our connections made we needed to make the final adjustment on our brake switch itself. Now the way we're going to do that is we're going to loosen or tighten the two nuts to either draw it in further, closer to the brake pedal arm which will push that plunger in, or we'll pull it away to let the plunger stick out some. Now essentially we want to adjust it to where we can have barely any bit of travel on the pedal before it comes on. So we're going to get it adjusted using a 14 and a 17 mm wrench for the two nuts. And the way you're going to know you have it adjusted correctly is the wire that's going to the front for a monitor wire, we're going to want to hook a tester up to that and when we just barely push on the pedal we want to get that signal letting us know that it has power.So about 1/8" of travel is what we're looking for. I'm just going to loosen everything up so I can get my switch started in the right position. And you're just looking for a little bit of that plunger to stick out, we'll do a real loose adjustment by hand and then we'll come back with those two wrenches and tighten everything up. So once we have it adjusted and everything snugged up, we're going to need to take a circuit tester and make sure that our indicator light is going to come on when we just barely push on the brake pedal. So since we have it hooked up to our six way up here I'm going to take my circuit tester and go to the appropriate pin, which if we're looking at will be towards the top, towards the passenger side. If I can get an extra set of hands just barely push on the brake pedal we can see that my test light is coming on so we are getting power. And that is how we are going to know that we have it adjusted properly.Now if you need to readjust it again, you just want to adjust it a little bit and then have somebody push on it while your testing this wire here so that you make sure that you have the proper amount of travel. You're just looking for about 1/8". You know how when you push on the brake pedal you hear that click to release it so you can put it into gear, that's about the same amount we want to be able to push and have power coming to the front here.So with all of our connections made, we can line our panels back up and put everything back into place. And that will finish up your look at the Road Master Stop Light Switch Kit, part number RM-751490 on our 2018 Jeep Wrangler JL unlimited.

Bruce W.


If you wire from the cold side of the brake light switch directly to the six pin connector won't it send a signal when you step on the brake?

Etrailer Expert

Jon G.


It will send a signal when you step on the brake, yes. What are you planning on doing?

Info for this part was:

Employee Joshua S
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Joshua S
Employee Jacob T
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Jacob T
Employee Chris R
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Chris R
Employee Kathleen M
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Kathleen M
Employee Dustin K
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Dustin K
Employee Jonathan Y
Video by:
Jonathan Y
Employee Robert C
Test Fit:
Robert C
Employee Ryan G
Test Fit:
Ryan G
Employee Clayton O
Test Fit:
Clayton O
Employee David F
Installed by:
David F

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