Brake lights 3rd ok tail nothing

96 chevy blazer 4x4 4.3 vortec v-6 have power at fuse constate turn lights on they work but no power for brake lights not even sure where to start looking 3rd brake light works fine any thing i'll try Thanks in advance Mitch

with your foot on the brake pedal wiggle the turn signal switch while keeping an eye on the brake lights. If the intermittently come on while your wiggling the switch than the switch is the problem. Apparently people have had success removing the switches and cleaning it with contact cleaner to resolve this problem. Of course check the bulbs to make sure they are not burnt out.

Just wanted to say thank you very much thats what it was it was in the signal I have another blazer just got to figure how to get the air bag off so I can get to the last screw to replace it But anyhow thank you so much for the tip Mitch