Brake Controller Stoplight Switch Circuit of 2001 GMC Sierra 2500 Not Working

Question:

I have a 2001 Sierra 2500 Duramax and dont have power on the red wire to my brake controller when I step on the brake pedal and no brakes setting at the trailer. I can apply the brake with the manual actuator on the controller. I have changed the brake light switch on the brake pedal. Still no power to the red wire or brakes. Any ideas? The controller is a Tekonsha PRIMUS iq.

asked by: Michael M

Expert Reply:

This is a pretty common issue for GM trucks around the age of yours. It's the third brake light fuse of your 2001 GMC Sierra 2500 that is blown. When it goes the brake controller activation circuit stops working as well. You can test this really easily by pressing the brake and seeing if the third brake lights up on cab above truck bed.

expert reply by: Jameson C