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Roadmaster Tow Bar Wiring Kit Installation - 2020 Jeep Grand Cherokee

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How to Install the Roadmaster Tow Bar Wiring Kit on a 2020 Jeep Grand Cherokee


Today on the 2020 Jeep Grand Cherokee, we're going to be taking a look at and showing you how to install Roadmaster's Diode Wiring Kit. Here at eTrailer, we install, test fit, and review a lot of different products to help answer your questions and ensure proper fit. When flat towing your vehicle behind your motorhome, there's five main components you'll need to do so. First is our tow bar, which is our attachment between our motorhome and our vehicle. In addition to your tow bar, you'll need your safety cables, which is a supplemental attachment, in addition to your tow bar. You also need your base plate, which is the connection point on our vehicle that our tow bar is going to attach to.

You also need your diode wiring, which takes all the lighting signals on your motorhome and transfers them to the lights on your vehicle so people will know your intentions when going down the road.And lastly, your supplemental braking system, which will take all of the brake inputs from your motorhome, send them to your vehicle, which will apply the brake inside your vehicle to help you come to a safe stop. These are available in a few different configurations. You can get just the diodes with wires, you can get the diodes with wires that also comes with your umbilical cable to connect your vehicle to your motorhome. And those are available in a couple of different configurations. You can get a coiled cable, a straight cable or a hybrid, which is partially straight and partially coiled.

And that's going to vary on your tow bar, which one's going to work best for you.Our customer opted for the Nighthawk tow bar, which comes with your six way connector. So our customer purchased the kit that just has the four-pole ends on it, because we can just cut off those four pole ends and then adapt it to the six pole using the parts that came with this tow bar. Your diode wiring kit is going to take all the lighting signals from your motorhome and transfer them to the lights here at the back of the vehicle. The diodes ensure that the voltage can only be directed from the motorhome to our light. And they act as a one-way check valve, so that voltage can't back feed into the rest of our system and affect any of the wiring or computer systems on our vehicle.

This is my preferred kit for getting lighting at the back of your vehicle. There are a couple of other options such as bulb and socket, which would require you to drill a hole inside your taillight assembly and add an additional bulb.That's a good option if you don't want to worry about voiding any warranty, because with the diodes, you do have to tap those into the wiring. Although I highly recommend the diodes over it because you have the potential chance for leaks down the road and stuff when you drill out and add the bulb. It does come with the stuff to seal it up, but over time it could definitely degrade.The last option is magnetic lights, which would stick on top of the roof and they just plug in right there at the front. They typically use a four-pole connector and this one of the quickest and easiest ones to get set up.

You just got to pull them out, set them on top and you're good to go. But they're definitely one of the most unsightly and you have to set them up every single time. So even though it's easy, it's still extra work. With the diodes, you spend a little more time upfront getting the install done, but once it's done, you never have to worry about it again. You just plug in at the front of the motorhome and you're good to go.We'll begin our installation here at the front of the vehicle, by starting at our base plate where our electrical connectors are going to mount and routing it back to our taillights. We've currently got the fascia off because we we're doing our base plate installation. And while you're doing that install, this is the perfect opportunity to install the rest of your components because you got all this stuff out of your way. Now depending on which kit that you purchased, if you got the one with just a four-pole wiring, it's going to have this end on it. That's what our customer had. We just cut this off because they do have a six-pole connector we're going to be attaching.If you have a kit that comes with a six-pole connector, this bulb won't be attached. You're just going to have bare wires like this. If you're planning on just using the four-pole, then you can just leave that attached. Since we're going to be replacing it with a six plate, we'll just cut it off and leave it out of here. From here, we routed our wiring around the backside of our bumper beam. And then we went across here, going out where the rest of our wiring goes. And we just routed it inside. There's a nice large opening there. We then just went straight back and I did attach it to the vacuum line that was here just to help keep it up because our braking system's going to have to tap into this wiring. Depending on the braking system you got, you may or may not need to tap into that.So that's why we kept it up here so we can tap into it. And we routed it just around. We attach it right here to the air conditioning line here, where it's wrapped in a sheathing just to help keep it up. But once again, we don't want it falling down. And then we go straight down from there. The two connectors that you see here are for my braking system. I went ahead and tapped those in. The braking system we're using is Demco Stay-IN-Play Duo. There are a few other braking systems that we'll need to tap into these wires as well. So that way the braking system can get a stop signal from your motorhome when you're hitting the brakes. They usually have wires that are color-coded just like ours are here. So green will just attach to the green wire from your diodes and yellow will just attach to the yellow wire.We just cut it, put that wire on, just twisted it together and crimped it here. So there's two and one. One of these goes off to the braking system and then we just reattached it right back to the wiring so it's a single wire coming back out the other side. We're also going to go ahead and hook up our ground wire. The white wire in our bundle, the four wires that we're routing back. This is our ground wire and we're going to hook it right to the bolt located here. So all I did was right where you saw where we had connected our braking system in, I went a little bit further down and I just cut the white wire and then it just actually just peels right back. So that way we can attach it right to there.Now you're going to get in your kit, a small ring terminal. Now this ring terminal here is a little bit too small to actually work on this bolt. So we're going to be upgrading it to a larger size. We've got these here at etrailer.com as well. When I take this bolt out, I hooked my braking system to it. So we're going to go ahead and remove the bolt and I'll show you the ring terminal that's on our braking system, because it was also too small. So there is a way to modify it. So that way it'll fit.I'll go ahead and show you what I did to that one. So that way it would fit if you don't want to buy a new one. But since this one's so small, I do really recommend buying another one just to ensure that it doesn't fall out of there or anything while you're putting it together, it'll just help save some potential headaches. So here you can see the other ring terminal. I just cut a little chunk out of it. So that way it would slide over the bolt and it actually just threads right onto it. We can thread it, unthread it. This is how you can make a ring terminal that is too small, potentially fit on a larger bolt. So we're just going to take this one off real fast or we could leave that one on there. It doesn't really matter. We just got to have both of our ring terminals. So we're going to strip back our white wire here.We're going to spin it around and twist it. Slide our ring terminal on there and then crimp it down. We can then take our bolt. We're going to slide our bolt through the ring terminal, and then we're just going to reattach it. And just make sure that tightens down nice and tight to where your ring terminals can't spin. They're nice and snug. Now we're just going to continue on routing our wiring to the back. We're going to be underneath next because we routed it straight down.So we continue routing it on and you can see that white wire again, this is the rest of the wire where we had cut. We only used the portion that goes from our ground that we attached to up there, that goes up to the front of the vehicle where we're going to put it on our six-way. This is just dead wire from the point where we cut here to the back. And it's okay, it's not hooked to anything, so it's not going to hurt anything to be there.We routed it behind the heat shield here to ensure it doesn't get too hot from our exhaust. And then we just continue going on top of our under shield here. We just poke it right on top and work them back. Just keep on working them back there above the under. You can see some little strings here where I pulled them through the holes, just feeding it through because sometimes it's easier to just poke it, feed it down the hole and then just work your way from one hole to the next, in order to get it routed. Because we just stay above these panels, just doing that all the way until we come out here on the side right here, this panel. And then we just stay above our rear suspension here, making sure to go above all those components.So we're way up there and we zip tie it whenever possible to any wiring. It comes out here. We just follow the factory wiring whenever possible because that gives us a good place to zip tie our wiring to, and our factory wiring is already routed in a way where it's not going to get damaged by any moving or excessively hot components. Now here you see our white wire. Once again, we went ahead and cut it at about this point and this can just stay here. This is a dead wire. We're not going to be using this. But the remaining white wire, I went ahead and just peeled the rest of that white wire off and then cut it because we're going to be using it as a jumper wire. It'll come in later. So our remaining three wires, we just route off following our factory harness towards the side or on the side of our muffler. We do go behind the heat shield that's here. And then it goes up from there.Now that our wiring's routed back, it needs to come out from behind our taillight assembly so we can connect it to the wiring behind it. So we're going to remove both our driver and passenger side taillight assemblies now, so we can get it routed up. There's two pins that hold this in. And on top here, well it's not necessarily on top, but you'll see a spot on your pin where it has a little cut-out and that's so you can take your screwdriver or a trim panel tool and stick it in that little slot there. And you can just give a little twist there and that'll pop out the center tab.From there, you can just grab the center tab and just pull it out. Sometimes the center will just pull out like that. If it does, this is going to stay in there, you can just put your screwdriver behind it and just pop that out. It'll come right out and then you can just stick those back together. So we're going to do the same thing with the other one here and then the two over on the other side. And sometimes they get a little stubborn. You can use a pair of pliers, just get behind it. We're not trying to cut this off. We're just using the mechanical advantage we get with our pliers here.Now the taillight assembly just pulls straight rearward to remove it. I like to use a plastic trim panel tool just to give myself a little assistance. Just poke it in there. And actually a lot of times, it just pops it right out and then we can just gently bring it towards the rear. We're going to tip it up so we can get to our connectors here. All the connectors are going to have this little red locking tab. Just pull that out. Then we can press on the release tab and pull the connector off. We'll then set this aside and get the other one disconnected in the same way over on the other side.So now that we're at this point, underneath we need to pull our wires up. But we're not going to pull the green wire up. That one's going to stay down below. So you can just cut in between the wires. You just cut with your little connector. We're going to have to do it on this side. So we'll just go ahead and show you that here. And if you have the one with the four-pole end at the back, you're just going to want to cut that four-pole off. We don't need it here at the back. And to get them separated, we're just snip right in between and then that green wire down below, you can just take that one and just peel it back like this and just peel it so it stays down there.And then the white wire that we had cut a small section out, we're taking that section that we cut out and we're going to bring that up here as well. So we'll have three wires pulled up on this side. So if you look straight down, you can see daylight down in the bottom. You can easily get the wires passed through, but it is too small for your hands and stuff. So if you're having a difficult time, you can use a piece of fish wire. We're using airline tubing, but at home, a metal coat hanger works out really well. You can just poke it down in there so it comes out the bottom. Tape your wires to it, and then just pull it back up. Now that we've got our wires over here, we can start making our connections. We're going to be using the wire off of the large connector and the small one that are both black, not the gray one here. That's for your reverse light. We don't care about that guy.We only care about the white wires. Some of them do have a stripe on them. On our driver's side here, it's a solid white and this one's a white with a gray stripe. This is going to be our stop and turn on the large connector. And this is our taillights on the small connector. I've already peeled back some of the sheathing so we could expose our wiring. You can do this with a razor knife if you need to, or you can really just unpeel it. It does unwind, but it's pretty sticky. So now that we've got that peeled back, I'm going to grab two wires that we want to cut. We're going to go ahead and snip both of these wires and then we're going to strip back each end of these wires. With each one stripped, we're going to take the blue spade terminals that come on your diodes, just pull those off and we're going to crimp a blue one onto each end of these wires.Now we can move on to the wires we had routed up. We got a little bit too much length here, so we're just going to get an idea. I want it to be a little bit excess and we're going to trim off what we don't need there. Be careful not to let these fall back down. We can then strip back each end of these wires. Since we cut the yellow and the brown, we are going to have to snip those in between again so we can separate those. The brown and the white wire now, we're going to twist together because we're using this white wire as a jumper to get our taillight signal on both sides. That's what our brown wire provides from our motorhome, is our taillight signal. So we're just going to twist those two.And since this is two wires in one, you're going to use that single yellow spade terminal that comes in your kit because it accepts the larger wires on the inside. Since we've got two, we've got twice the thickness. Let's crimp that guy on there. And then for our yellow wire, this is just going to get another one of the blue spade terminals. So now we'll take our diode and you can see they're labeled in and out. In has two spades on it, out just has one. Out is always going to go towards the bulb, so towards your light. That's going to be our connector side. So we're going to go ahead and plug that in. And we're plugging this into the white wire on our large connector, which means our in needs to reconnect our circuits back together. So we're going to go to the white wire that was attached before we had cut it here. We're just connecting those back together. Then we're going to do the same thing with our other connector that we had cut. The out's going to go towards the connector side.And then the other side of the wire, we cut there, it's just going to go right here to the in. So since the small connector here is our taillight circuit, that means it's going to get the brown and white that we've connected together. So we're going to slide that onto the other in. And our yellow wires, our stop light circuit, so we're going to bring this guy up and it's going to connect to the other in for our other diode, going to the large connector.Now, as far as the in, it doesn't matter which one's on which terminal on the in, they're both going to the same place. They're heading towards the out. Now on the back side of your diodes, there is an adhesive pad here, so you can stick it here on the inside, or a lot of times I stick them together so they're not clinking around. But due to the tight clearance that we've got back here behind our assembly, it can be difficult to get the diodes to fit. So we're not going to be peeling that off at all because it's just so tight. They're going to be held in there just by the pressure of being in there. So we're going to reconnect our taillight assembly now and then we can go ahead and put it back in place.And one of the things that you can do here with the wiring that I like to do is to use a zip tie and to tie it up here. This just helps ensure that the wires don't fall back down in there. So I'm just pulling our excess wire up there and we're just going to zip tie it right to the factory harness because our exhaust is right below that. And we don't want the wires falling down, hitting the exhaust and melting our sheathing off.Now just try to position your diodes in any open pockets that you can find in there. I know it is going to be tight, so you just got to work around with them till you find that sweet spot. And then it'll push right back in. We can then put our pins back in place and move on to the other side. We're going to route our green and our white wire over to that side. So we're back underneath now. We've got our green and our white wire. We go over top of the frame to make sure it's not going to fall down on our exhaust. We just routed straight across. We go over the frame on this side and then we use our fish wire trick once again to get our wires up behind the taillight assembly on this side.So now we're over on the passenger side and we basically did everything exactly the same over here. You're still connecting to the white wire to the big connector. On this side, it's white with a green stripe, and the white wire on the small black connector, which is white with an orange stripe on this side. The diodes hookup exactly the same, in between. The only difference is the color of wires that we routed across. Our green wire is going to be our stop turn signal. So that's going to go into the large connectors wire, the white and green there. And then the white wire that we routed across for our taillight circuit, that's going to go in between the orange and white striped wire here on this diode for the small connector.Once you've got those connections made, we can reinstall this side and we're ready to head up to the front where you can either test it out, if you just had a four-pole or if you're going to be installing a six-pole, then we're going to show you how to get that installed. Now, once you get your fascia on, your electrical connector here, we we're unable to install it before due to clearance and getting it to pass through. So we can go back and finish that up now. We've got our wiring here. We just pulled it through the opening after we put the fascia on. We are going to trim off some of the excess here because we don't need it. I do like to leave some excess, because it just makes doing any repairs or adding accessories, things like that, a lot easier if you can just disconnect this connector and slide it out a little bit so you can work on it.So we trimmed off that excess. We're then going to separate each one of these wires by snipping in between them. We'll then peal them back a little bit and strip each one back. Now this is going to vary slightly, depending on the kit that you purchased. If you did get the kit with the four-pole end and you don't have a braking system and you just need lights, you would actually just leave that four pole on there. If you've got a kit with a six-pole, then that's when we need to separate these and cut each one back. Now, some of the kits don't come with a four-pole or a six-pole because Roadmaster has plenty of tow bars available. And those tow bars come with your six-pole. So that's why there's kits that don't come with the six-pole since your tow bar may come with it. But this one came with our tow bar. So we're going to go ahead and slide the boot over our wires.And then we're going to take each one of these wires. I like to give them a little twist. It just helps ensure that none of the strands accidentally pop out of the hole and jump over and short out to another circuit. Once we've got all these prepared, we're just going to come over here to our connector. Everything's going to be held on using the Phillips screws that you see there. So we're going to loosen up the ones that we need. GD is ground, we're going to be using that one. That's our white wire. LT is left turn, that's our yellow wire. So we'll be using that one. RT is right turn. That's our green wire, so we're going to loosen up that one.Next is S. That is a not used one. That one's normally for your brake circuit, for a brake controller and stuff. We're not using that one with our flat tow. Next is TM, that's for our tail lights. We will be using that one. And then lastly is the center pin, which we're not going to be using either. This is typically your charge line circuit. So if you wanted to add a charge line kit, you would connect it to this post. This last one's just an open circuit. It's really used for just any other accessory that you might want to use it for. Oftentimes, if we do use it, we'll use it for powering up a monitor light inside your motorhome.Now that we've got them all loose, we're just going to go back around and push in each color wire into its appropriate location based on the label written on there. So GD was ground and white. So we're just going to slide that guy in there, tighten it back down, and then just continue our way around. Once you've got all your connections made, we can go ahead and re-install it. I like to take dielectric grease and fill up the back cavity here. And I like to put a generous amount on it to keep out any moisture and corrosion. And then after I slide the boot over it, I like to take some electrical tape and run it around the front and the back, just further helps seal it in and keep our dielectric grease inside of there. And we can take the screws that came included with our base plate and attach it right to our base plate attachment point.Now that we've got everything installed, the best way to test it out is just go ahead and hook it up to your motorhome. If you're by yourself, the easiest way to test to make sure everything's working properly is to turn on the flashers inside your motorhome, as well as your taillights. That's going to operate all the lights here at the back all at the same time so you can make sure they're working. Our tail lights are these outer lights here, which we tapped into and we can see it's working on this side, and it's also working when we look over here at the other side.Our left turn signal and brake light, they both share the same wire going back, that's going to be that yellow wire. And our flasher uses the same circuit. So since it's flashing, we know that this side's working correctly. And when we check this side, this side's also flashing. So we know the green wire, which is for the passenger side, is also hooked up properly. The jumper wire that we ran over, the little white wire, to bring our tail light signal to this side, we know is also working properly because we can see our tail light illuminated there, which means everything's working great and we're ready to hit the road. And that completes our installation of Roadmaster's Diode Wiring Kit on our 2020 Jeep Grand Cherokee.


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