Curt T-Connector Vehicle Wiring Harness Installation - 2018 Ram ProMaster City

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How to Install the Curt T-Connector Vehicle Wiring Harness on a 2018 Ram ProMaster City

Ryan: Hey everybody, Ryan here at etrailer, today on our 2018 Ram ProMaster City, we're going to be taking a look at and showing you how to install the Curt T-connector vehicle wiring harness. A lot of our ProMaster customers use their vehicles for work, so it's especially important to keep your trailer illuminated not only to remain safe and legal, but to keep your equipment that's on your trailer, safe as well. So since a lot of people do use these for work, chances are pretty good you're going to be hooking up to your trailer quite often and one of the big questions that we get asked all the time is if you're able to actually mount your wiring connector outside here to make it a little bit easier, and the answer is yes. Today we have ours mounted outside and it's not very difficult. You just simply have to drop your connector through the taillight pocket and route it over here where you want to mount it up.Now, in our case, I just used a couple of brackets and secured it to our hitch. If you want to set it up like this, you can find all these parts right here at etrailer.

Now, one thing that's different about this Curt wiring compared to some of the others is that this one is going to have a higher power output and that can really be useful say if your trailer has a lot of lights on it, or if maybe down the road in the future, you plan on putting some more lights on your trailer. The power that this delivers should be more than enough to properly eliminate all of them. So our four way flat connector here is going to come included with a nice thick rubber dust cap, which is going to help keep the terminals underneath it protected. Now, this is especially important, especially if you route this outside, like we have ours today.What I would recommend doing is every now and again, just to apply some dielectric grease to those terminals, and that's really going to help ensure that they stay nice and clean and don't develop any corrosion here. And because of that, this should last for a really long time and prevent any connection issues.

Now we've gotten some questions asking about if this wiring kit will disable your Rams Parksensor warning, and rest assured whenever we have this hooked up, that's not going to affect that feature at all. So that's going to be something you're not going to have to worry about. Now for those of you that will end up pulling a trailer that has brakes, and you're wanting to set up your ProMaster City to be able to use a brake controller, what you're going to need to do is pick up an ETBC-7 and you're going to use that kit in conjunction with this wire.Then all that's left for you to pick up would be a brake controller. And a couple that I really like is the Contra P two, as well as the Contra P three, they're really easy to use straightforward. It would be a good setup with your ProMaster.

So at the end of the day, a really well-built wiring kit, that's going to get the job done. Now, as far as the installation goes, it does take some time and can be a little bit challenging at some points. But I found a couple of tricks that will make that a little bit easy. Speaking of which let's go ahead and put it all in together. Now to begin our installation, we're going to be here at the back of our ProMaster.

You're going to want to open up your doors and we're going to need to remove our taillights. So taillights are going to be held in place by three large Phillips head screws.Once you have them pulled out, you can kind of close the door, maybe like halfway, grab the light and wiggle it and pull it towards you. Never going to need to disconnect it. So there's our electrical connector, can push down on that tab and separate the two. Now that I have this one off, I'll set it to the side and repeat that same process to get our other taillight off. Now we can do is grab our new trailer wiring harness over here on the driver's side. And we're going to pull the T-connector in, that has the red, yellow, brown and white wire into the taillight pocket. So what I've done is just use a piece of tubing as a pull wire. You can use it a string or a coat hanger or something like that too. We're going to go up through this large hole here. So I taped my wiring onto that pull wire there. We're going to feed it through there into our taillight pocket. Now we don't have a ton of space in here. So just kind of help feed that wiring down.Here's where our connectors are going to come out. Now we can grab our white wire with the pre-attached ring terminal. That's going to be a ground. So we need to secure it to the body of our vehicle. I think I'm just going to put it right here in the corner. It's nice, clean tech metal. And the way I'm going to do that is by using the provided self-tapping text group. Since our customer wants his wiring connector here, the 4-pole to be mounted outside. What we're going to do is take that 4-pole connector and again, tape it to the fish wire, just like we did the other connectors a moment ago is we're going to shut it down, feed it down into that taillight pocket.So here's where our connector comes out. And what I'm going to do is take our 4-way flat and just behind our bumper cover here, there's a small opening can actually take that connector, sneak it in there and push it all the way down. And that will end up on the bottom side of our vehicle. That way we can reach up there and get to it and eventually run it over to our hitch. And now we're going to do the same thing with our big bundle of black power wire, connect it to our fish wire. We'll feed it all the way out into the taillight pocket. So here's where our black power wire came out like the rest of them. And now I'm simply just continuing to run it down to the bottom of the vehicle. Just like we did that 4-way connector.Now what we can do is get our black power wire connected to this black power wire that's coming out of our module box. So this one coming out of the module box, it's already got a pre-stripped end. I'm going to take a heat shrink butt connector and crimp it on that end of the wire. Now the heat shrink butt connector doesn't come included. These just offer a little more protection. However, the ones that do come included will work just fine. If you'd rather use these, you can find them here at each trailer. So I got that crimped on. I'll just let it hang for now. I'll grab the end of our bundle of power wire that we just dropped down. We're going to strip back one end of it. And then this is simply just going to plug in to that other end of the buck connector inside. Okay. Crimp down. And I'll just grab my heat source to seal up our heat shrink ends.Now we can focus on is getting our green T-connector routed over to the passenger side. I think what I'm going to do is route it through this opening here, behind the sheet metal. Now I believe that our dome light here can be in the way of that. And so I'm just going to pop it down, take a Flathead screwdriver, and a pry on one side. And then if you go on the other side, you can kind of push in that tab so we can just let that hang down for now. So I went and routed my pole wire. It was all the way up through and down and out of this square taillight opening here in the taillight pocket, just like the other side it's now that I have our wire attached to it, I can start to pull on it and actually feed that wire down into here where we can, now that we have our green T-Connector in the taillight pocket, we can get it plugged in.It's pretty simple how this works. One end is going to get plugged into that factory wiring. The other end of the T Connector, simply just going to get plugged in to our taillight. This point we can reinstall our taillight the opposite way that we removed it. It's going to feed the wiring in, so we don't pinch it.Again, you may have to kind of open up your door a little bit and find that sweet spot to get everything aligned. Now we can re-install our dome light. So this will just pop back into place. Then if you move over here to our module box, we can actually get this secured. So what you're going to do is take the included two sided sticky tape peel off one side. You want to make sure the surface is nice and clean. Stick it to the module box and inside just inside of this pocket here, there's a nice flat surface and that's where I'm going to stick our module box to. So I went ahead and use some rubbing alcohol to clean off that surface as well. And I'll just carefully place this inside and push it into position.Now we can do back on the driver's side, taillight pocket is plugged in our T-Connector, works like the other side. One end plug into the factory harness. The other end will plug into our taillight, plugged in. We can simply just feed our wiring in and reinstall our taillight, the opposite way that we removed it. So now underneath our vehicle over here on the driver's side, this is where our wiring dropped down and I routed our 4-way flat connector to see some zip ties to secure it. When opened over our bumper beam, it comes out right here, ran it down, along through here, and then brought it to our bracket, which we have mounted on our hitch.Now these brackets are included, but you can pick them up here at each trailer. If you want to set yours up like this while I was down here, I also routed our black power wire, which is this here. Now, when you do any routing, you want to be sure to avoid any hot moving parts. So keep that in mind that being said, I just ran it up, secured it to the bottom of our vehicle, using some zip ties along the frame rail, following these factory brake lines.It's a little tricky to see, but it kind of runs in between our frame and our fuel tank continuing forward. Here's where our wire comes out, drop it down again, following that brake line. And then I just took off. There's a few fasteners kind of holding this panel on. I've just removed them so we could have a better look. But again, just continuing along those factory hard brake lines. And once we get right here, this is where our wire actually runs up into the engine Bay by our battery. Now, the way I got it up there was using a pull wire, kind of like we did at back at the tail lights. I dropped that pull wire down from our engine compartment. It came out here. I taped our wire to it, went back up top and simply pulled it up where we need it to go.So now if you pop the hood and then just compartment, here's where our power wire comes up. And what we're going to need to do is hook this to the fuse holder. That way we can put it to our positive battery terminal. So I strip back some insulation, take a feed, shrink butt connector, and crimp that on the other end of the book connector, we're going to take our included fuse holder, slide that in, crimp it down as well. The other end of our fuse holder is going to receive a ring terminal, slide that on, get it crimped. And then I can come back with my heat source and seal up our butt connector.This point we can hook our ring terminal up to the positive battery terminal. So I'm going to be removing this nut here. Using a 10 millimeter would pull this off. Some of these aren't designed to calm completely off of these very easily. So we'll find out if that's the case. If it is you do have a solution and you'll know that, that the nut kind of just wants to stop turning you kind of hit a hard spot, feels like this one is going to come right off. Maybe easier to use actually a socket when removing this.So the nut does indeed feel like it's going to come completely off, which makes life a little bit easier. Be very careful not to drop it, probably be difficult to find if he did. So from here we're just going to simply take our ring terminal and slide it over that stud and then simply just resecure our nut. But they're connected. Now we can grab our included fuse and install it into the holder. Now it's a good idea to test our wiring and make sure that it's functioning properly. I'm using this little tester and you can pick one of these up right here at each trailer. So we'll go ahead and use our left, turn our right turn, our brake lights and our run lights. And that'll finish up our look at it and our installation of the Curt T-connector vehicle wiring harness on our 2018 Ram ProMaster City.

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Info for this part was:

Employee Joshua S
Video by:
Joshua S
Employee Jacob T
Video Edited:
Jacob T
Employee Cole B
Installed by:
Cole B
Employee Ryan G
Test Fit:
Ryan G

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