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Roadmaster Brake-Lite Relay Kit Installation - 2016 Jeep Wrangler Unlimited

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How to Install the Roadmaster Brake-Lite Relay Kit on a 2016 Jeep Wrangler Unlimited


Today on our 2016 Jeep Wrangler Unlimited we're going to show you how to install the Roadmaster Brake-Lite Relay Kit for Towed Vehicles. Part number is RM-88400. This is what our brake light relay kit's going to look like. We've got our wiring harness here. Our relay is going to plug right into that. The relay acts as a switch that, in this case, is going to keep our brake light switch on our vehicle from overriding the blinker signal that's coming from our motor home.

Sometimes what'll happen is you'll have the blinker on in the motor home and the braking system in the Jeep presses that brake pedal. The brake lights come on on the Jeep overriding that blinker so it's no longer flashing; that could cause a safety issue for us. This is going to take care of that. Basically, the green wire and the black wire are going to take the brake signal through. When the ignition in our towed vehicle is not on it's going to stop it in the relay. Relay's got a little switch in there, it stops that signal from going through so it can't be overridden.

Once we turn the ignition on in the vehicle that signal comes in from the red wire, so once the Jeep's key gets turned on the switch is then closed. Once that's closed that signal's going to be able to pass through. When we're towing with our motor home we won't have any power from our red wire. That switch is open, that signal can't pass through. As soon as we get into it for normal driving operations the signal passes through and we'll have our brake lights on the back. Now, the blue wire is only for vehicles that have a push button ignition or on some Ford models, so we're not going to be using that.

We'll just get that snipped off just like that, set it aside. Then the white wire, that's just going to act as our ground. We'll use the provided ring terminal here, find a good grounding source underneath the dashboard where we'll be mounting this and get it connected. Now, they supply us with a short length of red wire. Typically this is going to be long enough to get to fuse panels located under the dash, but the Jeep doesn't have that.

The Jeep's is out underneath the hood. I'm going to use about 10 foot of 16 gauge wire, that's going to allow us to run out underneath the hood where we need to make this connection. This is part number 16-1-1, that's going to be a 1 foot piece, so you need to make sure you order a quantity of 10 so you get a 10 foot piece. That'll go right into our fuse holder which will then go out to our fuse panel. See we've got a fuse tap there, we'll use the red spade connector to go down on top of that, then we've got a couple of butt connectors here. We're getting a little bit longer in the kit, so we might have to add another butt connector, we'll just see when we get there. The first thing we need to do on our Jeep is to find the cold side of our brake light switch. What that means is there's going to be a wire that, when we press down the brake pedal activates. When we let go of the brake pedal it turns off. It's going to be right up at the top of that pedal. Usually about 4 wires that go in. We're going to go in right through here; it's located really high up behind the dash and it's tough to get to from the bottom. Just want to pull out here around the steering wheel at the top on both sides, so that door is kind of going to open up and it just slides off the 2 tabs there at the bottom. At that point we've got this plate here. There's 2 10 millimeter bolts in it. We're going to remove those and then we can just lift up on that plate and pull it out. Right in here is going to be the wiring that runs to our brake light switch. It's a lot easier to get to there, it's a lot easier to test there. Now you'll see that there are going to be 6 wires that run off of this brake light switch up through this wire loom that runs right up here under the dashboard. Now, we need to test these wires. We looked it up and it says that the brown and white wire is the one that we need to use. To verify that we're going to use a test light. Want to find a good ground, there's 1 right over here, or 2 actually right over here on the kick panel. Connect into and you'll see there when we press the brake pedal we get signals. As soon as we let go it goes away. That's the one we're looking for. Now, to make sure that we don't cause any issues with the theft deterrent system while we're messing with that brake light switch we're going to pull out the fuse right here. This is M37, it's a red 10 amp fuse, it's kind of to the passenger side of this large 60 amp here. We're going to pop that out, we'll just set it aside there, keep it pretty close to where we got it. We'll put that in once we get everything wrapped up. We just don't want to cause any shorts that might mess with the electrical system on our Jeep. We're going to pull the little keeper off, you can use a screwdriver or trim panel tool; this is what holds that wiring up. It's going to give us a little bit more flexibility in it. I'm going to strip back a little bit more of that black tape. Just want to be careful not to do any cutting of the wiring while you're doing it. Now we'll take our harness here, we want the green wire and the black wire. See they're kind of pre-stripped there so we'll pull the end off, get these twisted off, and we're going to snip them back some. Then we're going to add on a blue butt connector to the green side there. I'm going to add a blue one to the black side. It comes with a blue one and a yellow one. The yellow one's for use on the green side if your braking system ties into your stop light switch. Ours doesn't, so we're using a blue one that we've provided. You can use the yellow one, you just might have to double up the brake light wire on the Jeep. Now for the red wire we're going to do the same thing, add on another blue butt connector that we've provided. Remember we need to extend that out to that fuse panel, so we just want to have this on there and ready to make our connections a little bit easier to make. We'll go into our harness and we need to snip that white and that brown wire. Then we're going to strip the end back on both sides. All right, now to the side furthest away from the brake light switch we're going to connect our black wire. Slide that butt connector on and get it crimped down. Now the green wire needs to go to the brown and white wire closest to our brake light switch. Now for our white wire we're going to get it trimmed back just like we did the other 4. We'll add our blue ring terminal onto that. Now with a T25 torques bit I'm going to remove the screw that's located right here. Pass that through and then re-secure it. Now, if we come from our brake pedal here straight back to the firewall and then come over to the driver side we'll see this bracket where it comes down. Right behind that there's a little black grommet right here. This grommet, we're going to use to pass our red wire from the inside of the vehicle to the outside. It's a pretty thin material, kind of like a foam, so we should be able to poke that through. That wire is then going to come out just to the driver side or just to the outside of the brake booster there, be able to grab it and pull it on up through. We just want enough so we can get over to our fuse panel. Then what I like to do is run it right behind this bend in this wire, and we're going to go right across with it over to our fuse panel. I want to tuck it along the back side, then use some zip ties to hold it in place. From that corner I'm going to go right underneath this black panel, just put a little bend in your wire, it'll come around there for you. Just going to bring it down and in and zip tie if off down here pretty low. Now we've got plenty of extra wire here to make our connection up here in the fuse panel where we need to, so now we're going to head back underneath the dashboard there, get everything tidied up. Now we'll trim off whatever extra red wire we have. We're going to strip that back and of course that's going to connect to the red wire coming from the relay harness here. It's time to grab our relay and get it slide into position here. Just like that. Now we're going to bring this to an up and out of the way location where we can zip tie it off. We can bring our relay over here and there's going to be a nice bracket we can attach it to right below where we ran our wiring out of the firewall. Now we can just use a couple of zip ties and tidy up the wires running from that harness. We want to be sure we keep them up and out of the way where they won't cause any interference for the driver. Now for our ignition only power source we're going to come to the back side of the fuse box here closest to the engine. There's a spot open here for a long JK style fuse and we've got a 25 and a 20. That's for the power outlet inside of the vehicle, which is only on with the ignition. We're going to use that one. That fuse will be pulled out. We take our fuse tap and that slides right over just like that. Then you kind of squeeze it down on. You can see it hooks over the back of the fuse, and then that's ready to be slid right back in. Then we'll take our fuse holder here, separate it. Take our fuse out. I want my holder to stay right down here on this edge, so I'm going to split that, strip it back a little bit. That fuse holder, it just slides right on. We crimp it down. Our little extra piece of wire, we strip it back. The other side of the fuse holder will go on there. Determine the length of wire we'll need to get to our fuse tap. Strip that back and we'll add on our spade connector. All right. That'll go right onto that fuse tap. May have to bend it over just a little bit, which isn't a big deal. Going to run that right down this way, and you'll see right here this is where we'll need to make a little notch in the side of our fuse box to allow that wire out. We'll take our 10 amp fuse, we're going to slide that in. Slide the other side on it and that'll have that connection made. This will just tuck down here out of the way, that way it'll stay stored. Pop our cap back open and remember that little fuse we removed earlier It's time to put that back in. It was the 10 amp fuse we took out of that position right there. All right. Now to test it out what we'll do is with the ignition off we'll hit the brakes in the Jeep. As you can see, no lights are coming on. We then turn the key into the on position and we've got all of our brakes working as they should; our relay's working properly. With the relay working properly we're ready to put our panel back in place here. Put the cover back on and that's going to complete our installation of the Roadmaster Brake-Lite Relay Kit, part number RM-88400 on our 2016 Jeep Wrangler Unlimited.


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