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Roadmaster Universal Diode Wiring Kit Installation - 2018 Jeep JL Wrangler Unlimited

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How to Install the Roadmaster Universal Diode Wiring Kit on a 2018 Jeep JL Wrangler Unlimited

Shane: Hi, I'm Shane with we're going to be taking a look at, I'm going to walk you through how to install Roadmaster's diode wiring kit on our 2018 on our Jeep JL Wrangler Unlimited. This kit is going to allow us to transfer our light signals from our RV to our Jeep so we can safely flat tow it, which means when we turn on our blinker in our RV, the blinker is going to come on in our Jeep. Same thing with our brake lights and our running lights. So that other motorists can see whether we're turning, braking, or driving at night making it much safer to flat tow our vehicle.Our wiring is going to be one of five main components in a flat tow set up. The other four are going to be our base plate, which you're going to attach to the chassis on our Jeep to give us that solid connection point between our Jeep and our tow bar.Next is going to be our tow bar. This is going to give that solid connection point between our Jeep and our RV.

Then we have safety cables. Our safety cables are a second safety device in case our tow bar fails. And then comes our brake system. Our brake is required by law on any vehicle being flat towed and it allows the vehicle to stop itself while it's being flat towed.Now that we're gone over how the diode wiring kit works, let's go over what comes in the kit. We going to have our wiring that's going to run from our plug in the front of our vehicle to each tail light on the back of our Jeep.

We're going to have a ring terminal, self-tightening screw for our ground wire. We're going to have a butt connector, some zip ties, some wire loom to clean up our wiring once we get it installed. We're going to have diodes that are going to be connected to our factory wiring behind each one of our tail lights on our Jeep.Our diodes are going to serve a very important purpose. They're going to protect our factory wiring in our Jeep and our RV from any backfeed from either one if there is a wiring issue. How they work is your factory wiring is going to go in one side.

Your diode wiring is going to go in the other. They're both going to come out to your factory tail light on your Jeep. That way you can utilize those signals whether you're flat towing or driving your Jeep normal.One thing I do want to mention. This diode kit is not going to include this six volt plug. This plug can be purchased separately, and there are also diode kits available that have this plug included.

Another thing I want to mention is depending on which tow bar you choose, some tow bars are also going to have this six volt plug. Any of those can be found here at's walk through the installation process together. We have our wire running out here to the front because we're going to need to connect to our plug. I just kind of taped it up here to give me a little extra. Now I need to route it to the back of the vehicle. I want it through this pan, going over top of my base plate, over to my driver's side frame rail. There's a hard line right here. You can see I went over the top of it to stay away from my sway bar. I went up on top of my frame rail here, came around, went through my mount, came down and went inside of my frame rail.Now if you're an off roader this is a really good way to do this. Run it through the frame rail, how I did here. I went through here. I came out here. You're going to need some extra line to connect to my braking system. Came down, went back in my frame rail here. An easy way to do this is airline tube. Airline tube works really well. You can see the holes that are in the side of the frame. You can take that airline, you're going to tape the wire to one end of it. And you're going to feed that airline tube through each of the holes and just work it back to the back of the vehicle. You're going to see a large hole here in the back of our frame rail. This is where I brought my wires up. Once you get them out, you want to separate all of them.So the first thing we're going to do here is we're going to mount our ground wire. We want to make sure we're mounting it to a metal surface. Stay away from any plastic. Right here is going to be a good place. I'll measure it out and we'll cut our wire here. Strip it back, add on our ring terminal. I'm going to start my self-tightening screw first. Just like that.We're going to take our green wire. We're going to put it aside because that's going to be routed over to our passenger's side. We're going to take our yellow and brown wire, and we're going to route it up behind our driver's side tail light. In order to get our wires up, we going to have to remove out tail light. You need a flat head screwdriver, a plastic trim panel tool. On the inside there's a little cap. It looks like this. We're going to pop that cap off. There's going to be a plastic bolt in there that's on a spring. Take a 10mm socket and we're going to remove it. It's going to look like this. You're going to have the same thing on the other side.We're going to take our light. Pry it out just like this. Just like that. And for our plug on the back, pull up that red tab. You're going to push down here and pull out here. Like that. You're just going to do that same thing on the other side of the vehicle. And you can see where that opening is right by our gas tank filler tube. Get our yellow and brown wire up. You actually need to take your wiring, you need to strip back the covering on it. And it's just going to be some tape. It's going to be taped up to about here. You can see how far I stripped it back.Then we need to test our wires to determine which wire do what functions. We've determined that our yellow wire is our brake and turn signal, and this white wire with the gray stripe is going to be our running light signal.We're going to start with our brake and turn signal. We're going to cut our yellow wire. We're going to strip back both sides. I'd suggest stripping it back a little bit long because these are pretty thin wires. That way we can double it over. We're going to take one of our diodes, take the spade connector off. We're going to put a spade connector on each wire. Then I'll put in our diode. Single side where it says "out" is going to go down towards the plug. Other side, like that. That's going to complete our circuit. Now we're going to add in our running light and brake light signal from our diode kit, which is going to be our yellow wire. Your third spade connector, we'll add that on to our diode.Now that we've made that connection, when we're flat towing our vehicle that's going to allow us to run our signals back to our factory tail light. You can see we hooked up our diode the same way on our running light signal. This time we're going to take our brown wire. We're going to cut it to size, except the extra inaudible 00:07:01 that we cut off, we're going to strip back both of these sides, and tie them together. And take this large yellow spade connector. Make sure you crimp this down good so it holds on will. This is going to give us our running light signal. And then our extra brown wire, we're going to route it to the passenger's side with our green wire to give us our running light signal over there. Now we're going to take our brown wire, we're going to feed it back down through the hole where we brought our wires up.On the back of each diode you're going to have some sticky tape. Peel off the paper, and you can see how I have one stuck to the top of the other, and we need to stick this on a flat surface. I'm going to actually stick it right here. The reason we want to do this is so that our wires don't get pulled off if our diodes are just hanging. Now we can reinstall our tail light.Ran through, back through the frame rail. We have a hole on this side. 11mm socket. I took these two nuts down from my heat shield, ran my wire, green and brown wire, over the top where my heat shield. Put my two nuts back in. Ran it through the two holes of my frame rail on this side. Make sure I'm keeping it away from my heat, from my muffler. And now I can run my two wires up behind my passenger's side tail light.On our passenger's side you can see there's a small hole here. There's a big opening back behind it, you just reach up. It's about the same place as on the driver's side. Reach up, you can push your wires through there and grab them. Then we're going to do our connections the same here on our passenger's side. Our green wire is our brake and turn signal. We just connected our green wire into the end of our diode the same way we did on our driver's side. And then our running light signal is going to be our white wire with the red or orange stripe. Again, same way. The difference is we're only going to have the one brown wire coming to this diode.Next thing we need to do is we need to add our six volt plug onto the front of the vehicle. Again, this kit does not come with the plug. I'm going to be using the Roadmaster six volt plug that comes with the tow bar that our customer purchased. We're going to take this boot off. We're going to slide it over our wires like this. On the back of our plug, it's going to be marked. The TM is going to be your running light signal, which was our brown wire. GD is going to ground wire, which was the white. LT is left turn, which was our yellow wire. RT is right turn, which was our green wire.Now the plug, you can use a Phillips screwdriver or a flat head screwdriver. I'd suggest using a flat head screwdriver. These screws strip out pretty easy with the Phillips. But what we don't want to do is we don't want to pull the screws all the way out because they are very small. We're only going to go out about like that. We just want enough to get our wire inside. Now there's two other pins here that are available. For a flat tow if you want a charge line, you can use one of the pins. And then you have another accessories to add in something else.Now we'll add in our wiring. See how I had them stripped back here. You want to make sure that just the wire is going inside, you don't get the coating on there. You want the screw to go against the wires, that way you get a good connection.Now we're going to test out our wiring using an alternate power source. This is going to simulate being hooked up to your RV. Tail lights. Left turn. Brake lights. Right turn. Once you added any additional wiring, like our charge line we added here, it's a good idea to put some dielectric grease around your connections. This is going to help keep moisture from corroding them. If you don't have dielectric grease you can find it here at And all we want to do is just cover. And we'll take our boot, we'll slide our boot over the top. Take some electrical tape, go around this edge. And I'm going to take it all the way down over my wiring. Kind of seal off that end a little bit, like that. Take our inaudible 00:11:25.Now that we're installed the diode wiring kit, we're going to move on to the next part of our installation process for our flat towed set up, which is the braking system. I'm going to be making a video to help walk you through the installation on the Stay-IN-Play DUO. You can find that video here at under our 2018 Jeep JL Wrangler Unlimited.

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