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Roadmaster Diode 7 to 6 Wire Coil Kit Installation - 2016 Mazda MX-5 Miata

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How to Install the Roadmaster Diode 7 to 6 Wire Coil Kit on a 2016 Mazda MX-5 Miata


Hey everybody, Ryan here at etrailer. Today on our 2016 Mazda MX-5 Miata, we're gonna be showing you how to install the Roadmaster diode wiring kit. But before we do that, why don't we check it out and make sure it's gonna work for you So before we get too carried away I figured it'd be useful just to kinda touch base and refresh yourselves on the main parts that we're gonna need to flat tow our Mazda down the road in the first place. Now, usually what we do is actually be hooked up to the motor home and paint a real good picture. But today we have some really bad weather and so we're just kinda trying to make do so bear with us here. With that said there's gonna be a total of five main parts.

First one is gonna be your base plate, and the purpose of this is to provide us with a solid and reliable connection point, that way we can hook our tow bar up to it. Tow bar is gonna be the second component. And what this is gonna do is be the physical link that actually connects the front of our Mazda to the back of the motor home. Third main component will be safety cables. And these are just there in the event of an unlikely disconnect, they're gonna keep everything paired together.

Fourth main component will be the tow bar wiring. And what that's gonna do is transfer the lighting functions from the back of our RV to the back of our Mazda keeping us safe and legal. And last but not least the fifth main component is going to be the supplemental breaking system. And what this is gonna do is apply the brakes in your Miato, whenever you hit the brakes in your motor home helping to bring you to a more complete and predictable stop. So I just wanna kinda show how the wiring works here.

So we have a test box and again this is gonna assimilate our motor home. So the way it works whenever the motor home's lighting signals are sent back here, whether it be your taillights, brake lights, turn signals, whatever the case may be, it's gonna transfer through the wire and to the back of our vehicle, so let's go back there and check it out. Back here, like I said, we had our turn signal going in the motor home and it's being transferred back here. So when it comes to wiring, this kit is probably the best option for the Miata, and not even just for the Miata for almost all the vehicles out on the road, honestly, this is what I recommend the majority of the time. So we've had a lot of good luck with 'em, they're really reliable and they just work when it comes down to it.

So once you have it installed, you're not even gonna be able to see anything there, it looks factory with the exception of the connector plug up front but that's more or less inevitable. And I say that compared to some of the other wiring kits like Magnetic lights, for example, with those, they're gonna stick to your car, you're gonna have to run the wires up and over to the back of your motor home. And it's kinda just a pain, you have to set that up every time and you're worried about stuff scratching up your paint back here, and then eventually you're gonna have to store 'em too, right So you got a big bundle of wires with some lights. And as we know storage is precious whenever you're over the road. So having the diode kit, that's gonna stay with the vehicle, look factory and be super easy to use, it's definitely no brainer, at least to me. So it talked about that connector and so you'd take your cable, plug it in, the connector up front, the other end would go to your motor home. And that's how the signals are gonna be transferred back through there. Kinda speaking of the cable though there's quite a few different options, several different kits that essentially the only difference with 'em is what type of cable they're gonna have. And which one you're gonna need is really dependent on what type of tow bar you have. So, here today, we have the etrailer.com SD tow bar and this one has kinda this hanger deal where you can wrap your wiring around it, keep it up off the ground. And there's a lot of other tow bars that don't have this at all there are no channels or anything like that in it. And if you have a setup like that, you're gonna want the wiring kit that's completely coiled like this. So this is a seven way on one side, six way around on the other, super common kit. This is what the majority of people use and go with it works really good. For those of you that want something a little different, this is a seven way on one end, four way round on the other. But honestly, if it we're me I'd rather just have the six way that way eventually, if I wanted to do a charge line or add something else back here I would have the option to, right But this is still available. And then for those of you that have tow bars that have the channels in the side of it, you're gonna want a straight or hybrid type cable. That way you can actually utilize the channels properly. So a couple more options, this one's completely straight, seven way one end, six way around on the other. So you'd run it through those channels and utilize 'em. The other one is what's called the hybrid, so it's a seven to six and you can see part of it straight the other end is coiled. This would be good if you of like a really long tow bar, it's a pretty long cable, and it gives you a little bit of extra length but either way, as long as you got channels and a tow bar, it's gonna work as well. And then probably the least common that we see is the four way flat to four way flat. If this is one you have to use, it's available and it don't really matter what type of tow bar you have there 'cause you kinda get what you get, right And then there's one other kit that's available and it kinda comes with the bare bones at least, how I like to mention it. It's really just the bundle of wiring and the diodes and some of the connectors and stuff. And you would use that kit if your tow bar comes with a cable and comes with the connector plug some of the premier type ones do. If your tow bar has that stuff you don't need to go back and buy doubles by any means. So if your tow bar has all those, that bare bones kit is the one that you're gonna need. But other than that, at the end of the day if you need a tow bar wiring kit, really nice setup you really can't go wrong with them. As far as the installation goes, honestly it wasn't too bad, being such a small car there's not a lot of wire to run and things like that. You are gonna be working in the trunk for a little bit of the time. So kinda be prepared to kinda try to squeeze in there. But as long as you take your time, really shouldn't give you too many issues. Speaking of that though, why don't we go ahead and wire everything up together out To begin our instalation we're gonna be here at the front of our Mazda and clearly we have the front face removed and that's because we're doing the wiring at the same time that we did our base plate, which is what I suggest doing you just have a lot more room to work and everything else. But with that said, this probably can be done with the face on just gonna be a little bit tighter. Well with that said, first thing you're gonna wanna do is take one end of the bundle of wire and just run it over here where we have our mounting bracket gonna take the dust cover, slide that on. And then we can separate these wires, so carefully cut in between 'em. And then peel 'em apart a couple inches back. And what I like to do, is kinda cut a little bit of the end off and give us a fresh wire to work with. And then we're just gonna strip back the insulation a little ways on each wire to expose the copper wire underneath. And then you're gonna want to give 'em a twist to make sure the strands are nice and tight. And since they're all twisted, you can then grab our connector plug here and on the back of it, we're gonna have the terminals and they're gonna be labeled. And the way these are gonna work is you're just gonna back this set screw out, little ways, try not to get it completely removed, 'cause they're kinda a pain to get back in. But we're gonna have four, so this one will be labeled TM for taillight, so the brown wire will go there. This one's labeled GD for ground, so the white wire will go into it. This one is labeled LT for left turn, so the yellow wire will get connected there. And this one here is labeled RT for right turn, so the green wire will go into it. So we'll take our strip back wires here and make sure we have the appropriate one. We will then place it into the correct terminal and simply just tighten down our shut screw. I'm just gonna repeat that same process for our three remaining wires. So with all the wires connected, here's what it's gonna look like. And from here, you can take your dust cover, put that over, and we're just gonna secure it to the bracket there on our base plate. And one thing you can do is coat the terminals inside there with some sealer or some electric grease just to help prevent corrosion. I like to wait until the very end, once everything is kinda hooked up and ready to go, that way, if you do have to kinda get back in here it's not a big mess, so. We'll get this lined up and we'll zip it down just to kinda keep it in place. And then we can start to run our wire towards the back of the vehicle. So in our case, it just comes around here and runs along through there. And it will kinda come through right there. And I just ran it up kinda behind our headlight into the engine compartment. So in the engine compartment, here's where our wire comes up. This runs along through here. And then at this point it kinda starts to go towards the center. And then I simply just dropped it straight down along the firewall to the underside of our vehicle. And when you're doing this, especially in this area, make sure to do your best to avoid any hot or moving parts. So underneath the car now, this is where our wire drops down and there's some factory lines here that I essentially just followed. We wanna make sure to use some zip ties every now and again just to keep everything secure but that wire runs right through here. And you can kinda see it on top of this line, this continues to go back. And right here in this area I just took this, there's a small panel here with I think 4 10 millimeter head bolts so I remove that just make it easier to see what's going on. But it runs up and it's going to just continue straight back over our rear sub frame, and that wire, it's gonna come down right there. And right here, you can run it that way, so towards the outside of our vehicle. It'll come right here and at this point, we're just going to let our wire kinda hang for now. What we're gonna do is go up top and see what we got going on in the trunk area. That way we can figure out, where we need to get or where we can run our wire up inside. So in the trunk here, what we're gonna do is remove kinda all these panels in here, essentially, just so we can see what's going on and get everything routed up in here. So looks like, from what I can tell, all these are gonna be held in place with push pen type fasteners. So we're just gonna kinda work through and get 'em all removed. So to get those out, you can take a flathead screwdriver or even a trim panel tool and you're just gonna get underneath the head of it. Once you pop the head up, you can remove the fastener. So I'll just work our way all the way around and get them removed. And once we have 'em all out, we can start to kinda take our pieces and get 'em out of the way. So this plastic piece here that's gonna have four fasteners, which I removed. Manage to get this here, there's gonna be a little light that we'll have to disconnect to actually remove the panel, so there's a connector. And I'll just push down on the middle of it and while you're pushing down, you can pull it out. So, just continue to work our way around and get this stuff out of the way. Since all the panel's out of the way over here on the driver's side, we're gonna have a grommet factory grommet right there and that's what we're gonna use to get our wires up into place. So what you wanna do is kinda pull this out and then we're gonna make a small hole in the grommet, that way we can pass wires up through there. When you're doing this, be real really careful obviously you don't wanna cut those factory wires that are already through but I'm just gonna go off to the side, and take a pair of snips, and create a small opening. Once we have that opening made, we can put the grommet back in. Then I'm gonna reach underneath the vehicle and run our wires up into place. So pull the wire up through the grommet and just zip tied it tight, so it doesn't wanna drop back down. And then what you can do is like we did at the front, we're gonna separate just the white wire from the rest of our wires for now. So I'm gonna pull that back to about there and we're gonna have to cut this and ground it. So it turns out there's actually a really good factory grommet we could use right there. So I'm just going to eyeball the length here. And cut it, then we're gonna strip it back. And that wire twist, we can place on a ring terminal, crimp it down. And that bolt we're gonna pull out with a 10 millimeter socket. Take the bolt, slide the ring terminal onto it. And then we can just tighten it back down. Now, what we can do is disconnect our taillight wiring which is this wire here, it plugs into that connector, you could separate it by pushing down on that small tab and removing the two. And then what I'm gonna do is peel off this tape and remove this sheeting that goes around our wires. That way we can expose the wires and actually be able to work with them. So I got all that tape and stuff off our wires here and this is what they look like. And I also went ahead and just checked them for the functions. And what we're looking for is the taillight signals as well as the brake light signal. And so in our case, the brown wire here that's going to be our brake light or our stop wire. The red one is going to be for our taillights, and so that's where our diodes are gonna get spliced into. So what I'm gonna do, is go probably about halfway up the wire here, and cut 'em in half. And then I'm going to strip back the insulation on all the ends. And with these wires being a little thinner it's not a bad idea to strip 'em back a little bit further, give 'em a good twist and then kinda double it back on itself to make it a little thicker and it'll fit better into the connector. And on all four ends, I'm gonna do this and strip 'em back, fold them over and then take one of the blue terminals that come in the kit, place it over the bear end of the wire and then crimp it down. So I got all four of the connector ends put on the wires and now we can start to get our diodes going. So with the diodes, there's gonna be some sticky tape on the back side of 'em. I'm gonna peel that off, feel like this is probably be easier to do now. And I'm just gonna stick 'em together like that. And then the side that has the single terminal on it it's labeled out, you're here to plug that into the side closest to our taillight bulb, so right here, so you just kinda slide on. The other side will just go color for color, so, your brown wire's going into that diode, take the other of the brown wire, put it on either one of the terminals, don't matter. Same thing for the red. And now we can take our wiring that we ran up here and start to get that connected. So I cut it to length And the yellow wire I stripped back and crimped on, a blue terminal there. For the brown wire, we're gonna do something a little different, so with that one, we're gonna take an additional piece of wire. So I actually just used the leftover wire from when I cut this to length, we had probably six or seven foot of wire left over. So I took off the brown one just to keep it matching. And you're going to twist those bear ends together and you wanna make sure they're tight, so really kinda put some force onto it. Once those are connected, you're gonna take the yellow terminal that comes in the kit, place it over, and crimp it down. Now we're ready to hook up here. The brown wire, that's gonna be our taillight signal, so that's gonna go to the diode that has a factory red wire. That's gonna slide on. Since the factory brown wire is our brake light signal, we're gonna take the new yellow wire and get that one on. Then once they're hooked up, you can simply just take our connector and plug it back in. So with our driver's side hooked up, now we can run our green wire over to the passenger side, as well as that additional brown wire that we tapped in there to the passenger side too. So I just kinda follow this wire up along, running along the back of our vehicle, over to the passenger side. So over on the passenger side this is how I have our diodes hooked up. It's essentially the same exact thing as a driver's side. Factory wire colors are gonna be identical, so the factory brown wire will be our brake light, the factory red wire will be the taillight and so on our new green wire. But that being for a stop, I plug that into the diode with the factory brown and with the new brown wire being our taillight signal, I simply just plug that into the diodes that have the factory red wire. So before we put our panels back together and kinda clean everything up, it's a good idea to test our wiring and make sure it's working properly. So I'm just plugged in, to our round six-way connector here at the front, plug into a test box. You can plug into your motor home to do this as well but keep in mind if your motor home has any issues that can be translated back to this. But with that said, we'll try our taillight signal, our left turn, our right turn, and our brake lights. And that'll finish up our look at and our installation of the Roadmaster diode wiring kit on our 2016 Mazda MX-5 Miata..


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