brake lights only work when the headlights are on what would cause that? on 1990 Ford E-150

I'M trying to figure how to diagnose the reason why the brake lights on a ford econoline only work when the headlights are on. Could it be a short to power? I'm not sure where to start could someone give me any good advice? Its a 1984 by the way thanks.

by in Tacoma, WA on May 06, 2010
0 answers