Countrys1500GMC

Thanks. It’s actually the truck 3rd brake light. The one on the camper shell was working but I just removed the shell.

Hey there. So I have an issue with my 3rd brake light. I had a leer camper installed about 2 years ago. Just took it back off to move and now my 3rd brake light isn’t working. It has no power to it according to the meter. The cargo light works still but the brake like does not. Checked the bulb and fuses. All good. The installer swears they never disconnect them. But I can’t find where the power stops. Any ideas or diagrams off how the wiring is routed? TYIA.