I have a 1992 Pontiac Firebird and when the headlights are off both brake lights work properly. When I turn the headlights on the brake lights are also on without pressing them. Can tell I’m braking. Any suggestions on what the problem may be and how to fix it?
You may have a ground porblem either with headlights or tail light assemblies. These could just be dirty. Look around the headlight plugs and you will see one wire coming out of the plug and going to a nut on the body. The same for the tail lights. Remove the nut and wire a clean the surface. Clean the wire terminals on all connections.