ajcannon

Hey everyone, I am having a problem with the parking/running lights on my trailer when connected to my 2004 (1500) Yukon XL. I have verified that the problem is with my vehicle and not the trailer by connecting the trailer to two different (other) vehicles and the lights on the trailer work with both of the other vehicles.

When connected to mine, the lights will not work. I will point out that the brake lights and turn signals DO work - it is just the parking or running lights (not exactly sure what they are called) that don't work. The lights I am talking about are the lights that would be "on" when the headlights are on, even if the brake lights are not on at the time.

I have checked the fuse box (both under the hood and inside of the car) and found one fuse labeled trailer running lights and replaced that fuse, but that did not help the issue. I should also point out that the lights on the Yukon XL work as they should.

I have also replaced the 7 way trailer connector on the bumper but that did not solve the problem. I bought the Yukon about 6 months ago, and from the way that the wiring looks I am not sure if the previous owner ever towed with it or not. Everything (including the hitch) looks brand new.

I am wondering what I should check next? There are no visible broken wires under the car - as far as I can trace the wires everything looks perfect and very clean. Where do these wires connect at the front of the vehicle?

I've plugged a 7 way tester into the Yukon and the 12V light does not light up. All other lights on the tester act as they should.

Where do I go from here?

If it matters the trailer is a 1977 Airstream Tradewind, but again, I've double checked that the issue is not with the trailer itself by connecting it to two other tow vehicles where there was no problem.

Thanks for your help!

Joe In NY

they are called "Running Lights" and it sounds like there is a dead relay hiding in the mess behind the dash... not a fun job.

ajcannon

Oh joy. That does sound pretty fun.

Does the whole dash need to come out? Or can I get to it without removing the dash? Where should I be looking?

Thanks for your reply!

Joe In NY

Does you fuse box under the hood look like this:






If it does then try pulling the relay named "Park LP" its to the right of the trailer light fuses. I dont have experience with 2004 model and its been years since we had our 2002.

ajcannon

I believe it does - I will double check that tomorrow (or maybe Thursday - I've got a busy day tomorrow) and report back.

Your help is greatly appreciated - thank you!