I found out last night that my brake lights are out IF the headlights are on. If the headlights are off, they work fine. I've checked fuses and the bulbs. Any suggestions other than a short somewhere???

 

Probably a bad ground. The ground can pass enough current to operate the tail light filaments, but cannot carry enough current for both the brake light filaments and the tail light filaments. The amount of current that can pass is not enough to light up either filament. Look for a rusty ground connection, take it apart and clean it up.

 

Thank you - I will check that out this p.m. Lets hope its that simple ~

 

Not the ground - a mechanic friend of mine has seen problems with the light switch in the turn signal arm. `hoping for that......