The GMC dash tail and parking lights are on a different fuse from the brake lights. Check the fuses for a possible blown fuse.
I have replaced the entire brake system in a 1988 gmc jimmy and still have no brakes can you help/
Check the brake light switch. It's probably attached to the brake pedal, under the dashboard.
1994 gmc no brake lights 3 brake light works need help
There might be a separate fuse for the lower brake lights ( just a guess )
how to trouble shoot for gmc back up lights?
Begin by removing the brake lines from your 1995 GMC Jimmy brake booster. Remove the brake booster retaining bolts. Reverse the process to install your new brake booster.
The whole turn signal arm unit needs to be replaced
The 1996 GMC Yukon brake lights work by receiving power from the brake light relay switch. The brake light relay switch is connected to the brake pedal.
Hand brake? I thought the last GMC with a hand brake was in 68, but I could be wrong.
Bring to a shop that has an ABS scanner to determine the problem
Did you replace the fuse? have you checked the circuit board well the lights go on cause they tend to short out often