I have a 2006 GMC Envoy and I am having a problem with my passenger turn signal on my boat trailer. The brake lights and parking light work fine. The lights are LED. I have tested the plung on the harness at the bumper and all leads are fine except the one that controls this turn signal.

Trailer wiring uses the fuses for the car lights. Turn signal, running ans brake lights. Some plugs also charge the trailer battery if so wired. Check the ground wire for a good body connection. This wire often gets overlooked and can stop all trailer lights if it fails.

bad earth on the bulb holder or the wiring, usually a good clean should sort it out.

I would sugest a bad earth, 1st remove the brake globes & see if the sockets that house them are rusty, if so clean with emery paper & refit globes. See if this works 1st. ps don't forget to clean the globes contacts to

Suspect 7 pin connector problem , you should have power on the 8pm positioned and the centre pin position as you look into the socket (on vehicle. These pins are both male pins as you look at them . If ok check trailer wiring where it splits for either lamp assy ! Good luck

Short in wiring,, not hooked up correctly, check ground also, make sure all connected

RB

1) Look for fuse 32 in underhood fuse panel, I believe this is for trailer lights. 50 & 51 are for R and L trailer brake.
2) The blower resistor pack is defective, this is located behind the glovebox and mounted to the blower body.
3) I have no solution for tailgate problem, suggest visiting Trailvoy.com forum and doing search on XUV tailgate.

Try turning on the parking lights on the car, while hooked up to the trailer, then test the lights inside... Typically, there is not a full hot wire going through to the trailer....

It sounds like your have may have your brake light and running lights crossed on your wiring harness to the trailer. Good luck and hope this help's

try http://www.etrailer.com/faq-wiring.aspx. They have very good concise information that might help.

ok tdknutson, I'm not clear on this, does the truck left turn signal stop working when u plug the trailer in, or is it the trailer left turn signal that's not working, or both? When u plugged in the test light did it show u had power to that plug in? Let me know the answer to the above, and in the meantime, check the ground on the turn signal at the trailer. Make sure it's not loose, and tightly connected to the frame (or wire). Also, what type plug in do u have? 4, 6, 7 wire?