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Tekonsha T-One Vehicle Wiring Harness Installation - 2011 Mercedes-Benz Sprinter

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How to Install the Tekonsha T-One Vehicle Wiring Harness on a 2011 Mercedes-Benz Sprinter


Speaker 1: Today in this 2011 Mercedes Benz Sprinter we'll be having a look at and showing you how to install the Tekonsha T one vehicle wiring harness with a four pole flat trailer connector, part number 118650. Here's what a wiring looks like installed. The reason you're gonna want a four pole wiring harness like this on your Sprinter is so that you can safely and legally tow a trailer and have all the necessary lighting functions that are required by law. Our green wire is for our right turn signal and our right brake light. Our yellow wire is for our left turn signal and left brake light. And on those wires, we have a total power output of five amps, which is more than sufficient to have a small trailer or even a medium sized trailer with two or three incandescent bulbs per side or as many LED lights as we want because they do draw less power.

Our brown wire here, that is for our taillight and running light circuit. And on that circuit, we have seven and a half amps of power output. The white wire will provide our necessary ground connection between our Sprinter and our trailer.One thing that I like about this wiring harness is that we do have this built in dust cover here to help protect it from the elements, dirt and debris, and whatnot. One thing you can do is put some dielectric grease inside the connector, which we have available on our website. When you use with a cover, that'll even help protect it even further.

You can also use this dust cover here to secure it to the safety chain loops on your hitch. So when you're not towing your trailer, it'll be out of the way and not dragging on the ground.Some of our customers have stated when installing this that they found the power wire to be too short when attaching to your vehicle's battery. Well, that's simply not the case. We'll show you how to do that so you don't have to worry about having not enough wire. Matter of fact, when I installed this, I had extra wire left over.

We'll show you the right way how to route the wiring.Now that we've gone over some features, we'll show you how to get it installed. To begin our install, we'll open the rear hatch. Okay now on each side of our vehicle, we'll have five fasteners like this one. So we can remove this gray panel here that covers our taillight assembly. In order to remove these fasteners, we'll get behind them with a trim panel tool and pry back.

They are quite large, so it will take some effort to get them out. Now the top of the panel, we'll pull back away from the vehicle. And we'll do the same process on the other side.Now we're gonna remove our driver side taillight assembly. There's three T 25 torque screws. We'll remove these screws. Now we'll grab our taillight assembly and pull back. Now we're gonna unplug our drivers side taillight connector. There's two tabs. One at the top and one at the bottom. You're gonna need a flathead screwdriver to press down the tab as you pull back on the connector in order to disconnect it. Here's a better look at the tabs. They're really hard to get your fingers on. So that's why I recommend using a flathead screwdriver.Now we'll take the same connector and we'll feed it through the hole in our opening here. And we'll match it up to the corresponding plug that has the yellow wire on it. And we'll just push it in place until it locks. Now we'll take a roll of black wire. And on one end we will strip back some insulation. And we'll take our heat inaudible 00:04:08 butt connector that comes with the kit, place it over the wire, and we'll crimp it into place. Now we'll take the black wire that comes off our module, we'll strip back a little bit more insulation, and we'll stick that into the other end of the butt connector. And we'll crimp that down as well. Now we'll take a heat gun, which we have available on our website, to shrink down our butt connector. The reason you want to use a heat gun over a lighter is because this provides an indirect source of heat and it's not an open flame, which will damage the connector.Now we'll take our four pole flat connector and stick it through the hole behind our taillight assembly. Now we'll take our black power wire that we attached to our module, and we'll feed it through the same hole. Below our taillight assembly on the driver's side, there's a T 40 torque screw. We're going to remove this screw. With that screw removed, we can pull out on this plastic panel. And we'll get a gap. With that gap, we can now drop our four pole flat wiring and our power wire through that gap. And you can see it comes out behind our bumper cover now.We repeated the same process to get our power wire outside. Now we need find a place to mount our module. We're gonna mount ours down in this bottom of our taillight pocket area right there. I've already gone ahead and cleaned the surface with some alcohol and the backside of our module as well. Now we'll take our double sided tape, peel off one side, press it firmly against the back of the module, peel off the other end, and we'll stick it in place. And that's what it looks like in position. Now, the right wire coming off of our wire with the inaudible 00:06:24 is our ground wire. We need to attach this to our vehicle's sheet metal so we can ground the module properly. To do that, we'll use the provided self tapping screw. Now we can reinstall our bolts and our taillight on the driver's side. We'll make sure we plug our T connector into the taillight. And we'll click into place. We'll feed our connectors through the hole as we push our taillight back in place.Okay. We took our connector for the passenger side, that's the one with the green wire, and we routed it behind our headliner material here. You can just kind of peel it back and stick the wire inside. We did that all the way across the top here, making sure it went behind our latches for the door. And then it comes out right here. Okay, with our connector over on the passenger side now, we'll repeat the same process of unplugging our taillight assembly. We'll match up our corresponding ends and make our connections. And here's what it looks like with our connection made. Now we can reinstall our side panels. Now we'll show you how we routed our wires. Our four pole connector, we just routed behind our fascia here. We secured it with a zip tie. And then it comes down by the center of our hitch.Our power wire, we routed to the front making sure we avoided any moving parts and sources of heat, securing it along the way with zip ties. We just followed our frame rail here, followed a wiring harness towards the front. Once we reached our field tank, we went along the outside edge of it, securing it to the hanger straps for the fuel tank. Once in front of the fuel tank, we secured it to the battery cable, which goes inside our battery box, which is in our floor. Now we need to get the remainder of the cable inside the battery box. To get our wire inside the battery box, we'll just poke a hole in the grommet. And then we'll push the wire through the hole.Now we need to gain access to our battery. Our battery's in this general area here. That little battery symbol here. You need to remove this trim piece. There's supposed to be three torque screws that hold this piece in place. We only have two. With the screws removed, the cover just pulls right up. Now we can grab our carpet panel here and lift it up. Okay. This black panel here, our battery is located underneath it. There's supposed to be four screws our bolts that hold this panel in place, one in each corner. For whatever reason, ours doesn't have any. So we can just lift the cover up, set it aside, there's our battery.Okay. This black wire here, this is the wire that we pushed through. We need to connect this to our battery's positive post, which is right here. So what we're gonna do is measure off how much wire we're gonna need, cut off the excess, we'll strip off some insulation, take our remaining heat shrink butt connector, place it over the wire, and we'll crimp it into place. This is our fuse holder. As you can see, it's one continuous loop of wire. So we'll cut it in the middle giving us two separate ends. And we'll strip back the insulation from both ends. We'll place one end of our fuse holder into our butt connector. It doesn't matter which end that we use. And we'll crimp it. Now we'll take our heat gun and shrink down the connector. The other end of our fuse holder, we'll place on our ring terminal, and we'll crimp it down. Now this we'll attach to our battery terminal right here by removing this 13 millimeter nut. And we'll place the terminal over that stud and reinstall the nut.Now we'll take our fuse and stick it inside our fuse holder and close the cover up over it. Okay. With our connections made, we can reinstall our battery cover panel here. And we'll reinstall our carpet. Followed by our trim panel piece. And now we'll test out our wiring. We're using part number I26 on our website. It's a four pole flat tester to verify everything's working. You can also hook up to your trailer if you want to. We'll start by turning on our headlights. As you can see, our taillights and running lights are working. We'll do a left turn signal now. That's working as well. Followed by our right. That's working. Now we'll check our brake lights. Those are working. And with our foot on the brake, we'll double check to make sure our turn signals still work properly. Perfect. Everything's working like it's supposed to. And that completes our look at in showing you how to install the Tekonsha T one vehicle wiring harness with a four pole flat trailer connector, part number 118650 on this 2011 Mercedes Benz Sprinter.


Info for this part was:

Employee Jeff D
Installed by:
Jeff D
Employee Joshua S
Video Edited:
Joshua S
Employee Brent H
Test Fit:
Brent H

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