Hello. My son and I just out a new wire harness in his '74 camaro and everything seems to be fine EXCEPT the brake lights. We are getting nothing... Headlights, running lights, turn signals and emergency flashers work.. just no brake lights.. We also bought a new break light switch just to check and it is not working.. Suggestions?????? The harness is an American Auto Wire from Ecklers...

 

I don't have a wiring schematic for a 74 Camaro to trace the wiring, but in cars of that time period, the rear brake light and turn signal on each side usually used the same wire. If the turn signals are working in the rear, the problem is probably not in the harness. You need to check for 12V at the brake light switch to verify it has a power source. The brake light feed runs through the turn signal switch so it can cancel the brake light when the turn signal is activated. Otherwise, the brake light would not allow the turn signal to work in the rear while the brakes are being activated. Not an uncommon thing for the brake light contacts in the turn signal switch to be bad.