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Curt 5th Wheel Wiring Harness Installation - 2016 GMC Sierra 2500

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How to Install the Curt 5th Wheel Wiring Harness on a 2016 GMC Sierra 2500

Today, in our 2016 GMC 2500, we're going to be taking a look at showing you how to install the Curt Fifth Wheel Gooseneck Custom Wiring Harness and Seven Pole Connector. Part number C56070. Here is what our kid is going to consist of. We're going to have a seven foot extension cable. We'll have a C connector that's going to plug in between our factory seven way, and allow us to run an extension up. We'll mount this in the bed that way 00:00:30 we can plug-in or gooseneck or fifth wheel. That's going to come with some zip ties and some mounting screws. It is going to require that we drill a two and an eighth inch hole, once was located in an area we want to mount it in.

The standard for putting it in is usually in this area here, or some people put them up in here. Since this has a 90 degree turn, it's going to fit into a lot tighter area than some of the other ones in the market that come straight out the back. We determined from our customer that they want it right here. We're going to drill a two and an eighth inch hole there. Now, we already know that there's a whole bunch of room between here, because this is the thicker part of the bed, so we'll just go ahead and drill our hole.

Now, I'm going to take a file and just clean up our hole. Going to take a little bit of black paint and we're just going to touch up around the outside edge here, so we don't have any exposed bare metal, to prevent any corrosion. Now, we're going to need to go to the underside of our vehicle, so we can router wiring. We're going to locate the backside of our factory seven way connector, will pull it out on this great tab this going to release the lock. Then we'll push down in the center here, and we'll remove it off the back of the plug. You want to put a little dielectric grease on the inside of our terminals to protect them from any kind of corrosion.

If you don't have any, you can pick up on our website. It's part number 11755. Will take a little bit of grease, just want to kind of smear it around. We'll do the same thing on the factory plug. Now, we're going to snap this new T connector plug onto the back of our factory seven way. You want to give it a tug, make sure it securely mounted.

Then, we're going to plug the other end into the factory harness. Them will take our extension cable, we're going to route it across, we're going to take a couple of zip ties, we're going to tire wiring together, kind of hold everything up out of the way. Now, you can see we've got a lot of room in here. We've gone ahead and removed the spare tire just for video purposes. We can just trim off our access. At the other end of our plug, we're going to route up to the hole we drilled in the bed and push it on through. We'll put a little bit of our dielectric grease on this end, as well, then we can take it and snap it into position. Give it a tug. Feed it back down in there. Then, we'll take our supplied self-tapping screws. Now, we can take and bundle up our wire, and we'll attach it to the bottom side of the bed here. Now, if you decided you wanted to run a little further forward with your seven way connector, you've got seven feet of wire, so you can pretty much route this up to the front of the wheel well if you decided you wanted to go that far forward. Just want to make sure it's going to stay nice and secure up in 00:04:05 here. Now we can trim off our excess. Using the Tekonsha 00:04:14 trailer emulator, part number 6562 available on our website, we can see with nothing turned on, we have one light on there. That's going to be our 12 volt constant power. Now we're going to go ahead and test for a taillight circuit. Now our left turn signal, and our right turn signal. Followed by our brake. Perfect. Now we're ready to hitch up and hit the road. that's going to do it for a look at an install of the Curt Fifth Wheel Gooseneck Custom Wiring Harness with Seven Pole Connector, part number C56070, on our 2016 GMC 2500.

I F.


I dont have power the constant 12 volt contact. Any suggestions?

Etrailer Expert

Jon G.


Check any fuses related to powering the trailer. If that looks good then you'll want to check under your hood to make sure that you don't have to make any connections to your battery. Last thing to check is the actual wiring itself for any places that are damaged.

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