89 chevy 1500 brake lights not working. Flashers, signal, parking lights work and break fuse has power when the key is on. Found that that the brake switch has power when the brake is not being used with the ignition on - Lights not on. Depressing the brake pedal = no power to the brake switch with ignition on. Seams wierd ????

That is very strange. Check that fuse again. Maybe swap it with another fuse.

Check that fuse for power with your snowbrush jamming the brake pedal down. -- I had a case where the power wire feeding the fuses had a weak connection where it passed through the firewall. It would work until it heated up and then it would drop out. Hit a bump or wait till it cooled and power would be restored.

Thnaks - I did that and the circuit opened? I don't get why if there is power across the switch that the lights are not on all the time? Is there a relay or something else in the circuit ? been looking for a wiring diag but hanv ont found one that is detailed. I have the Hanes manual but it does not discuss or show very much. help

1. Make sure the bulbs are working. 2. Do you have all the wires making connections? 3. Is the ground wire connected and have a clean connection? 4. Are you getting power to the brake lights? If not is the fuse good? 5. The top brake light is on a different circuit, so the brake peddle relay is good. 6. My daughter MBZ had all her brake lights go out and it was corrosion on the light socket. (MBZ recall), check, clean and douse with some WD-40 to insure a good connection. 7. Do you have a hitch trailer connection? Some times that causes the lights to not function correctly. Try to see if you have power to the brake light circuit before disconnecting to see it that works. 8. Scratch your head, have a beer and cuss.