hi was wondering if any one could help when i have my headlights on and use the brake i get a blackout on all the lights on the a** end except for the rear window brake light. all bulbs are good. ???

1st up I WOULD BE CHECKING YOUR EARTH WIRES sorry are they disappearing completely or going very dull,are the bulb holders rusty?for a test: run a temporary earth wire to to your bulb holders and to a clean earth