Chevrolet Colorado & GMC Canyon Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
Hello all, 1st time Colorado and 1st time new vehicle owner here. 2018 Z71 v-6 4X4. Unfortunately my 1st post is not a happy one. I plugged my trailer up to the factory installed 4-pin bumper connector last week and promptly blew one headlight and signal on same side, and one taillight. Same trailer on previous vehicle 2007 Toyota Highlander for 11 years with NO problems at all. Plugged it in and my new truck high was gone. I have checked all under hood fuses and none are blown. I swapped a known working bulb in the dead holes and got nothing still. Could there be a relay blown somewhere? I will return with a happier post as soon as I get this dang thing figured out but for now I'm driving illegal.

Thanks to all.

Aye
 

·
Registered
Joined
·
1,236 Posts
I'd say either something's shorted on the trailer wiring, or there's a mis-match on the wiring harnesses...somewhere. Good luck...hope you get things figured out.
 

·
Registered
Joined
·
331 Posts
If it were me, seeing as it's so new. I'd let GM fix it. That's the whole point of a warranty. I by no means endorse dealerships to do any work other than warranty work.
 

·
Registered
Joined
·
1,036 Posts
A flat 4-pin trailer connector has four wires; ground=white, left turn/brake=yellow, right turn/brake=green, & tail/clearance lights=brown. To cause the problem you describe I suspect your truck side tail light circuit went to ground on the trailer. Check the trailer wiring before you plug it in again. It is likely that you have a 7-wire to 4 wire adapter under the rear of your truck that will need to be replaced but I have zero experience on the 2nd gen trucks so I could be wrong. Again!
 

·
Premium Member
Joined
·
247 Posts
Ditto with what ATMINSIDE said. Let the dealer deal with it.
Good luck
 

·
Registered
Joined
·
2 Posts
Discussion Starter #7
Thank you for all replies. I located a blown BCM fuse last night and all running lights are functioning again. Needless to say I was a bit tense thinking I had blown something major. "Body Control Module" sounds pretty major. Why one headlight and one tail light are wired into the BCM and the other two are not, well who knows. Now that I can breath again I will dig into the trailer harness again this weekend. Time to explore the forum now that all is good again. Thanks again.
 
1 - 7 of 7 Posts
Top