Troubleshooting Trailer Power Issues on 2015 GMC Sierra 1500

Question:

I have a 2015 GMC Sierra 1500. my trailer lights stoped working And the first thing I did was replace the plug. Next I found I had blown 4 fuses for my trailer lights I replaced them now I’m not showing any power to those 4 fuses. What could it be? Could I have messed up my fuse box?

asked by: Chris

Expert Reply:

It sounds like there could be a main fuse or relay that may be in the power line prior to those fuses. I recommend checking your owners manual for more insight. I assume based on my research your 4 fuses are mini fuses numbers 14, 15, 16, and 17. Check relay 64 as well. I don't believe you've messed up your fuse box, but I recommend taking it to a professional if you have issues after checking these.

I assume your trailer has a wiring issue that caused those fuses to blow, so I recommend checking your wiring using Hook Probe Circuit Tester # PTW2993 on the vehicle side when not connected and then using the circuit tester and a 12 volt battery until you know the wiring is correct. I've linked an article to assist.

expert reply by: Jason S