Tom Gondesen

So I hooked up my new 2023 Sierra SLT to my 2023 Coachmen Apex Ultralight with the standard 7 pin connector and got an immediate "Check Trailer Wiring" message. Took truck and RV to local trusted RV service man, who found that the ground on the wiring harness was not connected correctly at the trailer junction box. Just sloppy on Coachmen's part. Drove the unit home and parked it for 3 days. Hooked it back up to boogie and got the same "Check Trailer Wiring" message. Curse words. On the trip I used my Curt Echo wireless controller, which was not that snobby about grounding, and it controlled the trailer brakes just fine. But now I'm back to trusted RV service man, who showed me info about solar panels and GM trailering. To paraphrase, since I don't speak electric, GM is expecting a certain voltage through the wiring harness and the solar panel is exceeding that voltage. But there's another theory that the breakaway switch is interfering somehow. Personally, I think the Cardassians have done something to the trailer, because what do I know? Nada. Tonight, I'll try connecting after dark to check the solar panel theory. I will report what happens, but I'm looking for solutions. Anyone? thanks.