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Tekonsha T-One Vehicle Wiring Harness Installation - 2021 Jeep Wrangler Unlimited

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How to Install the Tekonsha T-One Vehicle Wiring Harness on a 2021 Jeep Wrangler Unlimited


Hi there Jeep owners. Today, we're gonna be taking a look at and showing you how to install Tekonsha's four-pole flat trailer connector vehicle wiring harness on our 2021 Jeep Wrangler Unlimited. And this is what our connector looks like when it's installed. You are gonna get a four-pole flat trailer connector with all the necessary lighting outputs which includes your left turn signal, right turn signal, tail lamps, and brake lamps, which will keep you DOD compliant in all States and ensure all drivers know your intentions when you're going down the road. One of my favorite parts about this harness is that it is a custom fit harness that includes its own module. What that means is that we've got connectors that'll plug in line between both the driver and passenger side taillight assemblies, and the module that's included with the harness will monitor all the signals that we're sending to the factory taillight assemblies.

It will then reproduce those signals and send them out on our four-pole connector here. What's great about this is that it separates this signals from our turn signals on our vehicle. So if there's any shorts or malfunctions on our trailer, the module will detect that and shut it down in the event that the module's unable to detect it and shut it down in time, it has its own dedicated power circuit with an inline fuse harness that comes included. The fuse will just open. You can repair your trailer and then just replace the fuse and you're packed up and running again, and at no point did any damage ever occur to your vehicle.

This connector is designed to live outside the vehicle. So there's a pre-attached dust cap that comes included with it. So you can keep out any dust, debris, and moisture, and you can also use this to secure it to your hitch's safety chain connection point. We do sell brackets available here at etrailer. These don't come included with your harness, but we have a no-drill bracket.

So you can easily mount things up without making modifications to the vehicle, as well as the four-pole bracket to give you a nice clean sturdy look for your four-pole harness. We'll begin our installation here at the back of the vehicle. We'll need to remove both the driver and passenger side taillight assemblies. We'll start on the inside here by popping off the cover so we can access the bolt. The cover's located just to the inside.

We're pretty much just going straight forward from where the taillight assembly is on the outside, but we're just inside. We're gonna pop this cover up with our flat-bladed screwdriver, and that's gonna reveal a single bolt inside that you're gonna remove with a 10-millimeter socket. Once you remove that bolt, the whole assembly will just pull straight towards the rear. We can then disconnect our electrical connector by pulling the red tab out. We can then press it on the release lever located behind it, and then separate the two pieces. We'll remove the other side in the same way. So now we're gonna take our wiring, and it plugs in right here to the factory wiring. So we're just gonna take the two connectors, plug it into our new harness. Go ahead and lock them in. This is gonna plug directly back into your taillight assembly when we reinstall it, but we're not quite ready to reinstall it just yet. Our module, we're gonna mount behind the panel here, and the green wire that's coming off of our module, it needs to be routed over to the other side. So we're gonna go ahead and get this routed over before we mount our module to make sure we've got enough wire length for the position that we choose to mount it in. So we're just dropping it down through the holes so we can come out the bottom. So we went ahead and pulled down the four-pole. We're just gonna let that hang there for now. Our green wire came down and we just routed it up over top of the frame here. I did remove these two nuts so I could put the wire on top of the heat shield. And then I just tighten the nuts back down. Wire then comes out on the other side of the heat shield and goes above the frame. Then we can just pull it out and plug it in like we did on the driver's side. Still on our module, we have a white wire and a black wire. Remove the white wire now, that's our ground wire, and we're just gonna run this into the body here, behind the tail light. We're gonna use the included self-tapping screw. We'll just slide the screw through the ring terminal, and then we'll line it up with our panel here at the back and just run it right in. And that's all we need for our ground wire. The black wire is your power wire on your module. You're gonna get a large bundle of black wire in your kit. We're gonna take this large bundle of black wire, strip back one side of it. I've dropped the rest down below cause we need to route that towards the front. We'll take one of the included heat shrink butt connectors, slide it on there, and then crimp it in place. The other side of this butt connector is gonna crimp onto the black wire coming off of our module. So that one's already pre-stripped once you pull it out of the packaging. So we're just gonna slide it in and then crimp it down. We can now take a heat gun to shrink down our butt connector. We can now mount our module box. We're gonna use the double sided adhesive tape to do so, but we wanna put some alcohol on a rag, and wipe down the area where we're gonna be sticking it to to ensure we have good adhesion. We can then take our double-sided adhesive. We're gonna peel off one side of the adhesive backing, attach it to our module. We can then peel off the other side of the adhesive backing, and then we're just gonna stick our module in place. So we went ahead and took some zip ties and zip tied up all of our wiring on both the driver and passenger side. This is just to prevent it from falling down if potentially hitting any moving or excessively hot components. Our wire came down, we just started following the top of the frame going forward. We wanna avoid anything moving such as our suspension here, and anything excessively hot like our exhaust. So we make sure to go up above our suspension. We come out right on the other side of the suspension, right about here, and we're real close to the frame right here, and we just follow down the frame, and then we go inside the frame here in this hole. We stay inside the frame all the way forward until we come out up here, and there's a bunch of holes in your frame and the way I got it down here is I would just feed it basically from one hole to the next. So I kept feeding it until I was able to get it out the large hole, just behind the driver's side, front tire. At this point, we could easily reach up to feed it up into our engine compartment to make our connections. So now we're back up above in the engine compartment. Again, I just fed that wire straight out from behind that fender liner from that hole that we had brought it out of the frame. And then after going straight up, I just tucked it behind all the little clamps going across the back top of the firewall here, and then just come right down to where our battery post is over here. So now that we're over here, and we got our wire over to our battery post, we're gonna go ahead and take the fuse harness that comes in our kit. We can cut this in half here, and then we're gonna strip back each end of this harness. On one side, we're gonna be placing the ring terminal that comes in our kit, and on the other side, we're gonna be placing a heat shrink butt connector so we can attach it to our black wire. We can now lift up our battery cover. We're gonna attach our fuse harness to it. You've got several posts here to choose from. We're gonna choose this one on the end since there's currently nothing attached to it. That's a great accessory post. We used a 12-millimeter socket there to remove the nut. We're just gonna take our fuse harness. We're gonna slide the ring terminal that we attached to it over the stud and then reattach the nut. And just slide our cover back on and put it back into place. You can poke your wire down if you want to to ensure that the cover still goes back on. So it's a pretty good spot for our fuse harness to hang out right here. It's easy to access. So now we've got our black wire right here. We just need to attach it to the yellow wire. So I'm just kinda matching up lengths because we don't need all this extra black wire here. So after you kind of figure out the rough length that you're gonna need to make your attachment, you can go ahead and snip off the excess black wire. We'll then strip back the black wire and connect it to the other side of that butt connector we attached to our fuse harness. Now that we've got all of our connections made all the way up to the front, before we insert our fuse, we're gonna come back to the back, clean up any of our wiring that we'd run with zip ties and go ahead and plug in our housings, and then just re-install these, and they can't be any easier to install because you just simply line it back up, push it in place, and then we can just re-install the single bolt that holds it in place. Now you wanna keep in mind, this is plastic. We don't want to over-tighten this. Don't use a heavy duty impact tool. Either do it by hand or use something with low power. This tool right here doesn't have very much power to it. So it's a great option. And that's all we're looking for there. We're gonna repeat with the other side. So now we can just take our fuse harness. We're gonna go ahead and open it up. Take the included fuse, install it in place, and at this point we're ready to test everything out. You can either hook up your trailer or use a tester. I highly recommend a tester over your trailer just in the event if your trailer has any faults on it. It may give you false readings, and you may think you did something wrong with your wiring, but it's actually your trailer causing the issue. With your four-pole, typically just route it over towards your hitch and you use the dust cap, and just wrap it around your safety chain loops to store it, but we do also have brackets available here at etrailer. We opted to use both a long bracket, which is a no-drill bracket that clamps around either your hitch or the frame of the vehicle. We clamped it around the frame cause on your Jeep here, you really don't have much on your hitch to clamp to. And then we put a four-pole bracket and attach that to the long bracket here and that just extends it out the back and makes it easy to access, and we've got a nice clean look without having to drill any holes or make any modifications to our Jeep. You don't have to worry about anything here ever causing a rust on your frame cause you had drilled some holes in it 10 years ago. So now we got ahead and plugged in our tester. We put the vehicle in the accessory position here. So that's why you hear the beeping, but you need to make sure it's in that position or start your vehicle and then operate all your lights. Make sure you have your left turn signal, right turn signal, check our tail lights, and your brake lights. With all the signals working properly, we're ready to hit the road. And that completes our installation of Tekonsha's four-pole flat trailer connector vehicle wiring harness on our 2021 Jeep Wrangler Unlimited..


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