Brake &signal lights on drivers side rear malfunction when head lights on.1997chevy 2500ck
1 Answer
Or it is a switch. The headlights should not affect the brake lights as they are different circuits. It very well could be as Tennisshoes suggested, the tail light board or crossed wiring. Depending on the abuse a 2500 work truck has had, anything is possible as far as damage goes. Checked for lose or frayed wires that are rubbing together.