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Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit Installation - 2021 Subaru Crosstrek

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How to Install the Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit on a 2021 Subaru Crosstr


Hello, neighbors. It's Brad here at etrailer. And today, we're taking a look at the Roadmaster diode wiring kit for a 2021 Subaru Crosstrek. Now, there are five required components when flat towing a vehicle. And the first one starting on the vehicle side is going to be the base plate. The base plate attaches to the frame of the vehicle, And that's gonna allow for all your connection points for your other components.

Now, going along with that, you see our tow bar here is actually attached to that base plate, and that's gonna make that connection between the vehicle and the RV. Next, you have your safety chains, and that's gonna attach to the loops on your base plate and also to the side of the camper. That way, if they do become disconnected for whatever reason, these chains are gonna hold this in place. Next, you have your braking system. Your braking system will allow the vehicle to slow and stop as you put those brakes on, on the RV.

Also included with that is gonna be this breakaway switch. So if all your components fail, this is gonna pull this cable, putting the brakes on the vehicle and bringing it to a stop, so it's not rolling down the highway. Next, you have your diode wiring, and your diode wiring is gonna send the turn signals and brake lights and the running lights from your RV to your vehicle. And this is all done based on this umbilical cord, which is gonna attach your six-pole here that we have on our vehicle to the seven-pole on the camper. So diode wiring is a really nice technology for a vehicle that's flat towed.

Many times, you'll see you have mag magnetic lights or even some wireless lights that transmit the signal from your motor home. Well, this is nice because it keeps it all integrated into your vehicle. It's less to carry around. And it's accomplished by sending the signal from your coach through the six-pole to the actual taillights in the vehicle where we have diodes in place. And it ties into the factory wiring, and it also prevents any back feed from occurring.

So it's gonna keep your lights safe, but also you're gonna have those signals ready to work whenever you plug into your camper. Now, included with our diode wiring is gonna be our umbilical here. So that's gonna allow our seven-pole here to attach to our six-pole on the vehicle. And that's gonna send that signal from the vehicle to the car, to the taillights, and that's gonna let people behind you know when you're braking or making turns and also just having running lights on. Many times, people think a car's trailing behind an RV with their lights off, and this actually lets them know that it is actually on and gonna keep you safe and legal during night driving as well as daytime driving. Depending on your flat tow needs, it can come in a few different configurations, and that's gonna be changing this plug. Everything on the vehicle side will stay the same, but you can get this coiled plug like you see here. You can also get a straight plug. You can get it without a plug, or you can also get it for a four-pole rather than a six-pole. Now, as far as the insulation goes, there's gonna be a little bit of wire running, but it's not too terribly hard. And when you get to the taillights, you'll be popping those out, cutting some cables, and making a few splices. But I'll be here to walk you through that, so let's take a look at that installation. We're gonna begin our install by running our wire. And so since this is gonna feed to the front here, I just went ahead and I gave myself a little bit of extra room and I take this down to where our six-pole is gonna go. And that way, we'll have this here for later. And then, I just simply followed our base plate here and kinda routed it up while we have our front fascia off. This makes it a lot easier to route this up. And then, I kind of routed it here. You can see the zip tie. I actually have my wires tucked in to the radiator's support, and then just kinda went back this way. Now, you're gonna see at this point, I split off my white wire, and the reason being is this is gonna be our ground, and it can really be grounded anywhere throughout the vehicle. But we have a factory ground here, so it's gonna be nice to have one point where all of our grounds go. And that way, if we have any grounding issues, we can then go back to this one contact, and we know that this is gonna be good because it's a factory one. So what you're gonna wanna do is with the four wires, you just kinda split with a wire snip, just to get that white one separate, and then you're gonna wanna peel that back. Now, what I did is I cut off the excess, so I don't have to run that white wire back, and you're left with a decent amount. In fact, this is how much extra I had. And this is gonna come in handy when we actually go back to our taillights because we are gonna have to jump them from one to the other, and sometimes finding extra wire can be tricky. So getting our ground up this early means that we have that extra wire for the back. So let's go ahead, we'll get a ring terminal on here, and get it on our ground. So we'll go ahead and strip off the end of our white wire. And then, included in the kit is gonna be a ring terminal, so we're actually gonna use that. And we'll just crimp this down. I'll double mine up just a little bit. Now, we'll go ahead and get this ground screw loosened up. Looks like it's gonna be a 10-millimeter. Now, it's kinda tight here, so to get that off and make sure that we have a handle on that screw so it doesn't fall down, I'm just gonna take off my fuse panel cover. And that makes it all quite a bit easier to get our ratcheting wrench on there. Now, with our ground screw taken out here, we can go ahead and place it here on our ring terminal. And I'm seeing that it is pretty close to the same size. Not to worry, I'm gonna go ahead and just make a tiny little clip here, and that way it opens it up and allows this to sit on there. You can also run a drill bit through here just to enlarge it just a little, but I'm gonna just make a quick little cut here, and that's gonna allow us to kinda open that up here and get that stud on there or the bolt on there, I should say. Kinda squeeze that through, and it's still gonna hold on there quite well as you can see. And then, make sure if this came loose, you have that slot there that kinda slides back in. And we can now go ahead and get this tightened in place. So with this ground screw tightened down, we can continue our routing. And I simply just kinda follow it along here. You're gonna wanna make sure you have just a little bit of extra slack just to make it a little bit easier to run, but kind of tucking back here underneath the brake master cylinder. I started to route down. Now, the steering rack, you can see it right here, is protruding and you don't want that to make any contact. So I've kinda routed it a little bit lower, and I'm gonna go back with a few zip ties and kinda just find some points down here just to make sure that it's not making contact with that. Now, this car in general, being all-wheel drive and having exhaust that kinda routes underneath the way that it does, it does make it a little bit tricky to run this because during all of your wiring, you're gonna wanna make sure you're staying away from any moving parts that can pinch as well as exhaust, and that way it's not gonna melt. So let's get under the car and I'll show you how I routed it to the back of the vehicle. So you can see our steering column there and our wire. So I'm gonna go back with a few zip ties and just kinda using some of the plumbing lines around there, just kinda get this to where it's going around that steering. We're not gonna want that to make any contact. And kinda looking at where I've routed it, if you can route it a little bit tighter here, that's gonna work pretty well. And then, I just simply kinda went through here. We have our underbody kinda covering. There's a plastic tab here. I just popped that out, ran our wire through, and put that back in place just to kinda hold it tight against the chassis. Routing it back, I went over this little crossmember here. And as you can see, like you're exhaust, again, is pretty close to this, so you want to try to avoid that as much as possible, as much as you can. But here, we're actually using this underbody panel to kinda protect it. And then, from here, we are going to route it into the center part of our frame rail here to keep it all protected. Now, you're gonna see that yours has probably a plastic cover, so you're gonna wanna remove that. And there's just a few 10-millimeter bolts as well as some plastic pushpins. And you're also gonna wanna remove the rear one, which has a few 12 millimeters as well as some plastic pushpins. So go ahead and get those out, and you're gonna see this is gonna be nice and open. Now, you can route this along here using zip ties, but you do run the risk of if you make contact with anything on the road, that if it pinches that wire, it can damage it and then you're gonna have to trace your wire. So routing it internally here, I know it's gonna be protected. Now, it is kinda tricky to route that, and I'll show you a little trick of how we got this routed down. We used a spare air line tube. It's basically just a pull wire. So if you have a hanger or anything to route electrical wire through walls or whatever it may be. Basically, I just pulled this grommet out, and I fished this down to our end, taped this up, and I was able to easily pull that through here. I made my way back to this grommet, and I've just made a slight little cut here. I'm gonna go back with some black silicone just to make sure that's sealed up, but that way I can actually put this back in place. And then, I continued to route it, put a little zip tie here on our brake cable. And then, going up near the gas tank, I went up and over. You can see, again, there's a lot of moving parts here. You have your axles, you have suspension arms, so making sure that you are staying away from there and finding little points to zip tie it up too to make sure it's secure is gonna be ideal. So routing it back here, kinda come back to where they have their trailer hitch. Also, the exhaust isolator bracket, I used that. And then, we're gonna be able to route this over to the corner where our taillight pocket is gonna be. So from here, we're going to be making a few attachments, but we're also gonna be reusing that fish wire technique to get these wires ran. So let's get that started. Now, we are gonna have to remove both the taillights to gain access to the plug, and that's where we're gonna be tying our diodes into place. So in order to get your taillights off, you see these little plastic caps here, there's a little notch there. You can go ahead using a flathead or a trim panel removal tool like this, you can go ahead and remove those. Just kinda pry up and they should kinda pop out like that. And then, you're gonna see there's gonna be two 10-millimeter bolts there, so we'll go ahead and get those off. And then, as far as taillights, sometimes they can get a little bit tricky and fight you. I kinda just give 'em a wobble back and forth as there's pins that actually kinda go into slots, and sometimes, just pressure alone can kinda keep those kinda tight. So giving it kind of a forward push or a pull here, and then wobbling it back and forth tends to loosen it up like that. So this is where you can see those kinda push into these slots, and then these slide onto there, and that's kinda what's fighting you sometimes. So this gains us access here to our taillight wiring, and this is where we're gonna be tying in to put our diodes. So let's just go ahead and we're gonna get this unplugged. We'll push our tab down here, and then this should work itself out here. There we go. And now, I'm gonna set this aside where it's safe, and we're gonna go ahead and test this. And what we're gonna be using is just a probe here. So we're gonna find a nice grounding point here. I'm just using our latch that we have for our hatch, and I'm gonna just run through the light sequence to figure out our running lights, our brake lights, and our turn signals just by testing each of these and seeing how they react. And then, I'll make some notes to let you guys know which ones are which, and that way we can denote what color wires we're using. Gone ahead and removed our driver side taillight as well, and I went through and tested it with our light probe, and this is kinda what we came up with. So on our driver side, our running light is going to be, it's a light blue color. Our left turn signal is gonna be the white wire. Our brake light is going to be a brown wire. Now, on the passenger side, you have that same light blue color. The right turn though is gonna be green. And then, our brake light will be brown, just like our driver side. So on our driver side, we're gonna go ahead and use that fish wire technique that we kinda used on the frame. And we're just gonna take my air line tube here and just pass this down, and we should find it kinda tucked under here. So we'll get a hold of that. So now, we're just gonna make this connection with our wire on our pull line just by taping this up. And just kinda make sure that it doesn't get caught as we're pulling it up, I wrapped this front or leading edge, I guess you'd say. Once we have that, we can go ahead and feed this up. Now, once you have this pulled up, double-check under here to make sure that you're pretty happy with the way that it's routed. And as you can see, we still have a little bit of slack, but if we make sure that it's nice and taught where we want it down there, we'll be good up here to be able to cut off some of the excess. Now, from the factory, Subaru has wrapped this up with a blue tape, and then a black electrical tape as well as some heat shrink here. So we are gonna have to peel this back to gain access to our wires, so we can splice into them. So I used just a razor blade to kinda peel back some of it. Just be careful that you're not cutting any of the wires, and get this pulled back enough probably to about this area here. And I'm gonna trim this tubing that goes around it as well, just so we have the exposed wires. It's gonna make it a lot easier for us to tie into it. So just a small little, oh, actually it's split for us, so that's pretty cool. And this excess here, go ahead and cut this off, get it out of the way. So with our sheathing kinda peeled back, we have our wires exposed. We have quite a bit of excess of our three wires that we pulled up, so I'm gonna go ahead and I'm just gonna clip right about here. That's gonna give me plenty of room but also make it a lot easier to work with here. So we'll go ahead and clip this, and then we can also go ahead and separate these wires and get them stripped. So on our diodes, we're gonna see we have these little spade connectors, and this is how we're gonna kinda make that jump in between these wires to the wires that we ran. Now, at this point, we're gonna find our white wire that we stripped up by the ground, and we're gonna be using this to tie into the brown wire. And you're gonna see on the diodes, there's gonna be one that has a yellow spade connector, and that's just gonna be larger gauge since we have both of these wires attached. So let's go ahead, we'll just get our white one attached now to our brown. And we're gonna be jumping these, and that way they share the same signal from each light. This kind of connects the two. So let's go ahead and get these twisted up. Okay. Now, with all of your connections, I suggest kinda going back, give it a slight tug just to make sure the wires aren't gonna pop out 'cause you really don't wanna have to go back and trace a loose wire. So knowing that they're good, each connection you make is gonna make it a lot easier overall. Now, the rest of this white wire, we can actually just route through this pocket, and we'll be pulling this over to our other side. But for now, let's just get this down and out of the way. Now, this green wire is also gonna need to route over to the passenger side. So normally, you can use this extra and peel the green back and get it over there. But I really don't think this would've been long enough, so I'm gonna extend this wire with extra white wire. Now, using two white wires to extend it can get a little bit confusing, especially once we route it over there. So in order to make sure that we have the proper ones, just go ahead, you're gonna wanna make sure that you have enough to route over to that other side, and I'm gonna make a little cut, and then I'm gonna tag this. And that way, I know which one's attached to the brown and which one's attached to the green. So let's go ahead, we'll route this over, kinda make sure we have a little bit of excess. We still have plenty here, so I'll go ahead and I'm gonna make this cut here. And then, I'm gonna put a little electrical tape on here, just so I know that this is gonna be our brown one. So now with our green wire pulled down, we're gonna route this together again with this other white wire. Now, that one is marked, so make sure you do that, and that's gonna save you a little bit of time. And what we're gonna be doing is connecting this with a heat shrink butt connector. Now, this is not included in the kit, but I highly recommend these. Any connections that you make that live kind of outside the vehicle or can be exposed to water, this is gonna kinda just cinch up with some heat, and that way it's all protected. You're not gonna have that corrosion of the wires or any moisture causing damage. Now, if you need some heat shrink butt connectors, we actually have these here at etrailer, and they're nice for any wiring project that you might be doing for any auxiliary stuff on your vehicle. So once you have those crimped down, just go ahead, get some heat on it. And these will cinch up. So now, we have are joined together white and brown, and this is gonna jump over. We're gonna be tying into our running light here, which is gonna be our blue. And you're gonna see this is where we got our spade connector here. And really, this is kinda just gonna go in between here. So that way, your factory wire is going in, as you see, and then out towards where that plug is. So this lives in between, kinda makes that jumper, and then this is tying off of it. So we're gonna go ahead. We're gonna cut this small wire here. And if you get too close to the plug, it can get kinda tricky just trying to get everything in place. These wires are small and kinda sometimes tricky to work with, so I go a little bit further back. And we're gonna go ahead, and we'll splice these ends here. And then, using our spade connectors that we have on our diodes, we'll go ahead and get that connected. Again, just like before, double-check your connections. Make sure they're tight. So now you're gonna wanna take that same diode and you're gonna see in and out. So you're out is gonna go towards the taillight, so the closest one to the plug will go on our out. And then, our in we're gonna go ahead and attach the other part of that blue wire as well as our jumper wire here that we have. And that's gonna be our first diode connected. So now, we need to go to our brake lights, and that's gonna be our brown. And we're gonna go ahead and get our diode and do the same thing. So now, you can see we have this all hooked up. We're gonna repeat the same process on the other side, using those wires that we ran across. So the yellow here is gonna be the left turn signal. That green that we extended with the white, that's gonna be your right turn signal. So keep that in mind when tying it all together. And then, once you have that all tied together, you can see there's double-sided tape on these. You can stick 'em together, you can zip tie 'em, but either way, with these connections, I actually like to go back with a little black silicone and just fill all those up. And that way, those stay protected from any moisture buildup, and that way they don't get corroded where those plugs are. So I've gone ahead and I routed my extended wires over, and I just kinda followed the inside of the bumper. There's some plastic supports that I just kinda zip tied those up, and it keeps it away from the exhaust. Then, routing it up, I just kinda followed the same principle, and I re-taped this marked line, and this was gonna be the one that we jumped off of the brown wire that went to that doubled-up spade connector. So that way, you can denote the two there. And then, I simply just tied into our blue wire here, and then we have our brown wire on this one. So at this point, we're gonna go ahead, I'm gonna stick these together. I'm gonna go ahead with my black silicone, kinda fill these gaps here, and then we're ready to plug in our taillights and I'll hook it up to a power source up front, so we can test to make sure that the lights are working. So we have our diodes ran. I plugged in our taillights. So really, we just need to test this. And so in the kit, you're gonna see you have your six-pole here. And so we're gonna go ahead and kinda get this started the wiring up so we can test this. So first, we have our little boot here. We're gonna slide that on. And that can kinda just live over here for now. And then, we're going to go to our backside here with a small Phillips. And on each little terminal here, you're gonna see a few letter designations, and that's gonna kinda give us that, pretty much tell us where these need to go. And so you're gonna see you have your ground, which is GD. That's gonna be our white one. Our next one here, it's gonna be hard to see but it is LT. That's our left turn signal, so that's gonna be our yellow. Our next one's gonna be our right turn signal, which is gonna be our green. And then, our brown wire, this is going to be our TM. So our TM here, that's our trailer marking lights. We'll be using that as running lights. And then, you also have a, this is where your 12 volt charge is. And then, your S, we're not gonna use it for this. That's gonna be a different auxiliary one. So for now, I'm gonna get these lined up, and then I'll show you how it looks, and then we'll test it out. So here we have it all put into the correct spots. I've tightened these down. So now, we're gonna hook this up and see how it works. We're gonna be testing using a test box, but you can also hook it up to your RV to get the same signal. So now, let's run it through our actual sequence here. And so starting off, we have our right turn signal on. Next, we're gonna go to our brake lights. Then, we're gonna do our left turn signal. And then, finally, our running lights. Now, at this point, if you have more flat tow components to add on, you can continue on with that. But if you're stopping here, you're ready to get this mounted up and get your fascia put back on. And that was a look and installation of the Roadmaster diode wiring lighting kit on a 2021 Subaru Crosstrek..


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