Hey Laura, just as a side thought I have had, if you live in CA I believe you now qualify as a lemon car. Same problem 3 times to the dealer constitutes lemon by CA law. You will need to look into it a bit further but the dealer should now be responsible for all costs of repairs. Again I'm not 100% but it is worth looking into. Sorry to hear about all your problems.

I'm having the same issue. All fuses are good, and all relays I can access check out. Everything on the trailer plugs and trailer works, but I have no park lights on the truck. The brake and turn signals work, and the park lights on the LED mirrors work. Both the run lights are none. I can power up the circuit from the rear tail light with a power probe and all lights come on. The headlight switch is good. So there's gotta be some sort of junction box or relay I'm missing.

Any luck with your problem Spastik Monkey?

Fixed. I had to replace the CJB

Got it fixed, it was a burnt wire coming from the headlight switch that went to the engine compartment. It was melted completely in half.

Thanks for the update,, glad it was an easier fix...