My left turn signal on my trailer harness isn't working, i have narrowed it down to the wiring on my vehicles side. I've looked through my haynes manual but can't find where everything terminates. Anyone have a suggestion?

 

Ha! I don't think there was ever a factory trailer harness, so I don't think Mr. Haynes will be able to help you.

The trailer harness (dealer installed, I'm told) on mine ended up forward of the left tail light cluster. For you, I'd try looking on each side.

Be prepared for an adventure. The tail light cluster is wired through a single connector, so you can remove the entire cluster if need be. The rocket surgeon that installed the trailer harness on my truck cleverly attached (using the despised "vampire" crimps) some of the wires on the harness side, and some on the cluster side, of the connector. To remove the tail light cluster, I'll have to simply open the connector, then hack through half of the trailer wires.

 

Good to know, mine must of been dealer installed as it looks very professionally done. Ill have to do some adventuring. Thanks for the intel!

 

There must be a connector on vehicle side, correct? Did you probe that?

 

I installed a trailer plug adapter in my 93. It plugs into each rear tail light assembly and then runs down to the receiver. If yours is the same, it's likely a poor connection at the plug or a broken wire somewhere between.