denf221

This may sound strange, but my headlights dim considerably when I press the brake pedal, any idea why?

svnt442

Bad ground somewhere.

Yellowstatue

Look behind the headlight mounting, on the engine side and there should be a small screw holding the ground wire to the rad cradle on each side

denf221

thanks

joe_padavano

I've had this problem before, and unfortunately it can be almost any of the connections between the alternator and the lights. Certainly check the grounds, but check everything else, too. In my case, it was a corroded terminal at the junction block on the horn relay. The resistance caused low voltage whenever the current draw was high (ie, when the headlights and brake lights were on at the same time).