1999 GMC Suburban, K1500 4WD. Top brake light bar

above the brake pedal.

brake pedal arm

this one is tricky. I know that gmc had a problem with the hazard button dropping out the brake lights except for the third light. There was a recall so you may be in luck if it includes your vehicle, or it maybe switch that detects the brake being depressed. I had that problem w/1999 Jimmy and my cheap fix was to jump each side off the third brake light. I used the top bulb in assembly and disconnected the wire that feeds the brake light but left running light wire on. Havent had a problem since.

Check fuses..check light pigtail to make sure it is connected

i have a 95 gmc suburban that keeps blowing the fuse when break is aplied i even disconected the back lights and it does the same what could it be

on brake pedal switch has a hair pin clip pull it un plug switch slide it off pedal etc.

Try checking the wires on the harness going to the brake switch. I have the same problem, and there was a short in one of the connections. the bad thing about it, it is hard to get to with out dropping the column. Hope it helps.

Sound like you have a wheel sensor going bad.You will need a scanner to monitor the sensors while driving to see which one is causing the problem

One of two things cause this corroded or poor chassis earth at the bulb holders or the circuit board that holds the bulb is faulty.

This is a well documented problem, replace the turn signal/multifunction switch to correct this issue, this very problem happened on my GMC, it is a 99 as well, replaced the switch as instructed by a chevy forum member and it fixed the problem