joekarter73

Can't speak to anyone else's issue but mine (2021 Colorado with a trailer that just worked with my 2018 Silverado) ended up being a high impedance (cruddy connection) with the ground to the frame on the trailer. Not how I would have wired the trailer originally (I'm an ****** retentive electronics tech) but instead of running the ground to each of the lamps they bonded it to the frame near the tongue and then bonded each of the lights to the nearest frame section around the trailer. Cleaned up the first connector and viola everything works. My suspicion is that they designed the system to "look" for a certain level of return current and if it's not there the system shuts the power off to the plug. And now, since I have everything apart anyway, it's off to the part store for LED replacement lamps. Hope this helps'