[SOLVED] trailer plug not working

davidmeyer · May 22, 2026

hello, I'm new to this and not sure if this is the right place for this. I have a 2016 gmc yukon denali and I only have 12 volt aux and left turn signal/brake on the plug. Have checked voltage on all pins and disconected harness and have same issue at the harness. any suggestions. thanks

LsHart · May 22, 2026

Blown fuse my guy!!

Fless · May 22, 2026

The underhood fusebox should have individual fuses for the trailer lights. Left turn/brake, right turn/brake, and running lights. The 12v AUX fuse is likely a larger J-Case fuse and you know that's working. Your owner's manual should have a diagram of the fusebox and the separate fuse positions.

Also verify that the ground connection is good in the 7-blade socket, because if that's not solid it may affect all of those circuits (and that can also depend on where you're getting your test ground).

davidmeyer · May 23, 2026

LsHart said:
Blown fuse my guy!!

thanks

davidmeyer · May 23, 2026

Fless said:
The underhood fusebox should have individual fuses for the trailer lights. Left turn/brake, right turn/brake, and running lights. The 12v AUX fuse is likely a larger J-Case fuse and you know that's working. Your owner's manual should have a diagram of the fusebox and the separate fuse positions.

Also verify that the ground connection is good in the 7-blade socket, because if that's not solid it may affect all of those circuits (and that can also depend on where you're getting your test ground).

thanks i'll check

davidmeyer · May 23, 2026

davidmeyer said:
thanks i'll check

had two blown fuses. thanks for the help

davidmeyer · May 23, 2026

davidmeyer said:
thanks

had two blown fuses. thanks for the help

[SOLVED] trailer plug not working

davidmeyer

TYF Newbie

LsHart

Senior Member

Fless

davidmeyer

TYF Newbie

davidmeyer

TYF Newbie

davidmeyer

TYF Newbie

davidmeyer

TYF Newbie

Similar threads

Forum statistics

Latest posts