Hello. I need help with the wiring for my tow hitch for my 2019 Chevrolet Express 3500 LT Passenger van. There is a plug at the back bumper but it does not match any standard towing plus, either 4 pin or 7 pin. Also, under he driver side front carpet, I see what looks like someone had an electronic brake hooked up to this van since the wires are taped off, unsure what the two other plugs are that are taped to the wiring harness (white and green plugs). I do have a standard 4 pin wiring harness that connects to the tail light wiring, but if I can utilize the rear plug, I would prefer to do that. Any help would be appreciiated.

This plug is at the back bumper but not standard wiring plug for towing

Looks like someone had an electronic brake hooked up? Not sure what the white or green plugs are for.

 

I’m not going to pretend to have your answer as I am in the same boat with my 2019 Chevy express 3500. I have done enough research though on other forums to tell you that many of these vans that did not come with a factory tow package did have some level of pre-wiring for the brake controller. I think that’s what you’re looking at under the floorboard. Some vans have blunt cut wires for your brake signal and power to hook up your aftermarket trailer brake controller. Verify with a test light but I believe that’s what it is. Find the blue wire it should only power up when the brake is pressed and the red wire should only power up when the ignition is on. I don’t know what the plugs under your back bumper is I think mine has the same.

does your van have back up sensors in the bumper? If not that plug may go to that option.

 

Thanks for the reply. No, I do not have the backup sensors on my bumper. I have taken the van to a trailer company, they sent me to a auto wiring specialist who was unable to figure out the towing wiring, then I took it to my local Chevrolet dealer, they looked up the wiring schematic and said it is not wired, so to get the 7 pin wiring for my towing needs, I would need to run lines from the rear bumper up to the front of the van and tie into the brakes, electrical box, etc. It's doable but I think for the time being, I am just going to use the simple wiring harness that connects to the rear lights for 4 pin towing. This has been much more difficult than I thought it would be.

 

I have a 2018 Express 3500 that I set up for towing. It did not come with the factory tow package either. I had to run the wiring for both the four and seven pin connectors, as well as the brake controller. It wasn’t difficult do myself in just a few hours. I do recommend a second set of hands because there is a lot of getting up and down on the ground if you don’t have access to a lift. I purchased a wiring kit through etrailer.com that included everything needed for the installation except the brake controller. The attached video is very meticulously done and walks you through the entire process. I purchased the brake controller and class V receiver through Amazon (less expensive than etrailer).

https://www.etrailer.com/tv-install-...van-90195.aspx

 

You can go with a blue tooth brake controller like I did, you don’t have to mount a controller anywhere and you don’t have to wire anything for the brakes except for 12v fused power To the plug. I then bought the tail light connected from etrailer to hook up The brake and turn lights, and so far I am pleased.

 

Matt I am in the same boat. Did anyone ever figure it out??

 

i'm in the same boat as well! apparently those wires run to the engine fuse box. in the lid it shows which fuses are for the TRLR (trailer) loom, but there is no way to put fuses in those spots so apparently the 2019 express 3500 passenger didn't make the cut for the upgraded fuse box -.- thanks Chevrolet!!! Glad I have that cool switch to light up my dash with!!! so back over to etrailer to figure out how to run and wire everything LOL!
R.

 

As an update, I started checking pin outs in the fuse box using factory wiring schmatics. I had the same wires under the dash as pictured above but I did not have the RPO code for trailer wiring provision (forgot what that was UW3 or something like that). The wires do not make it all the way the fuse box and probably terminate in the harness somewhere or at a connector. I ended up wiring it the way E trailer did with running all my own wires using a plug and play harness from E trailer to get signals from the rear lamps for tail/brake/turn and using a add fuse tap to get the brake signal. From what I can tell for the most part, if you dont have the round connector on the rear frame rail, you dont have any useable trailer wiring from the factory.

That being said, I am up and running and have 5000 miles so far. Pretty impressed with this beast

 

I had the same problem with my van, I searched and searched for where the Blue & Red wires emerged but no luck. I was tempted to plug them into 120 VAC and use a circuit tracer to find them.
All I could use was the fuse position, the interior ground, and the stop lamp switch wire.

 

I have been trying to get information about the connector at the back of the truck, near the bumper. I located a number on it and searched it and found the following custom wire connector associated with that number, but it says it is for a Chevy Traverse. Has anyone ever tried to use this?