I have an 89 chevy k1500 with no brake lights. the brake switch is fine and all bulbs are new. everythings getting the right voltage but when you press the brake pedal, no lights. any suggestions or a link to a wiring diagram?

 

with the brake pedal engaged have you checked for voltage at the light socket?

 

yes there is voltage, There is voltage whether you depress the pedal or not.

 

check the ground's on the tail light assembly's them self's ,also there is a printed circuit board in the tail light assembly that like's to corroded and fry ,the can be found relatively cheap at o'reiley auto parts .