Newbie here. I was trying to connect my trailer wiring to by splicing into the existing wiring harness using a 4 flat connector. My left turn signal which should be yellow, does not seem to be working. I troubleshot to the first disconnect under the body and that is fine, so I figure it goes further up. Any ideas? This vehicle has never towed. Now if it is a wiring fault from GM, will they honour it and replace it? Thanks.

 

It's probably disconnected in the engine bay. And I don't see GM fixing it unless you've got an extended warranty....even then....probably not.

 

Thanks, where in the engine bay would I find the bundle? All the other lights for the trailer, just the left turn signal. Grrrrr.

 

i'd take a test light and make sure you got power to trailer plug with trun signal on first. does left turn signal work on truck ?

 

had the same problem as you ..on your right hand front fender you have a fuse box ..open it and change the fuse ..

 

Thanks, yes my normal signal lights work, just the trailer connector left signal is not working. Thanks black powder I shall look into that tomorrow.

 

If you have a Multimeter you should check the voltage, if you dont have one then go to radio shack and get one for 10 or 20 bucks. Disconnect your trailer from the truck connector. Turn on the right turn signal and check the voltage between the right (green) post and the ground. Put the left signal on and check the voltage on the yellow, it should give the same voltage as the green. If both are reading the same voltage then you have a problem with your trailer wiring or bulbs.

 

Thanks folks, I feel stupid, it was a fuse. I didn't know each side had it's own fuse, let alone the trailer lighting had its own fuse. It was one of the 10 amp fuse under the hood/bonnet. Thanks Blackpowder!