Troubleshooting 2018 GMC Yukon Trailer Wiring Harness Where Right Blinker Lights But Doesn't Blink

Updated 07/16/2021 | Published 07/15/2021

Question:

I have 2018 Yukon and having trouble with the right turn/brake light green wire boat trailer lights. When I activate the right turn signal, the Yukon light blinks but when I use my tester at the Yukon plug in, I get a solid light and no blinking. Works fine for left turn signal. Likewise, if I plug in the trailer lights, no blinking on the right, just a solid light. Left side works fine. Help!!!! Thanks

asked by: Michael H

Expert Reply:

It sounds like there might just be a blown fuse on your 2018 GMC Yukon, since they will have fuses that are devoted to the towing functions. You'll want to check the engine compartment fuse box in fuse slots 39 and 40, to make sure the fuses are in good working order; I also recommend cleaning off your trailer connector to ensure that it's free from corrosion.

If you can confirm there aren't any blown fuses, let me know and I can give you couple of other things you can look at to try to isolate the issue.

expert reply by: Erik B