Tail Lights on 2008 GMC Acadia Stop Working when Trailer is Connected

Published 06/17/2016

Question:

I installed the product 118451 trailer harness on my 2008 gmc Acadia but when I connect the 4 way pole connector to a device i.e a trailer the brake lights and turn signals stop working on my Acadia and I dont know if I need an extra fuse that I may have to add or if I did something wrong. Can someone help?

asked by: Isaac

Expert Reply:

Let's start with the easy stuff. Make sure the white ground wire on harness # 118451 is attached to a clean bare metal surface on your 2008 GMC Acadia. There can be no coating or paint and it works best if the wire is grounded by itself.

If that doesn't help then what is probably going on is the trailer lights draw more power than the vehicle wiring system can handle. You can test this by removing the connections to some of the lights. Then, if everything else starts working, including the lights on the vehicle, then you know the issue was too much power draw. Switching the trailer to LED lights will solve that problem since LEDs draw a fraction of the power of incandescent lights. I have linked the LED trailer lights we carry.

expert reply by: Michael H