Hey folks, having an issue with no reverse lights when the taillights are connected to the trailer plug wiring. The reverse lights do work when the trailer plug wiring is bypassed.

I know very little about electrical so any information and insight would be much appreciated. I have attached a photo for a visual.

Thanks,

Dig

Left side - not connected to the trailer plug wiring (reverse lights are working)

 

This when a trailer isn't even connected right? So you've isolated it to the added-on trailer loom. I assume you've already visually inspected the wires. I'd take apart the other end and look at the plug. There might be some loose wires in there or corroded terminals. And make sure the ground is well grounded.