MG Car Repair: headlights 69 mgb, high beams, light bulbs

Question
Headlight low and high beams will not turn on, Parking light do work, switch works, everything else seems to be work fine

Answer
Hi Peter,
Use your test light to check for output power with the lights turned on at the blue w/white and the blue w/red tracer wires coming out of the dimmer switch. If you have power one each when flipping the high/low switch then check at the head light bulbs and also check to see that the black wire at the bulbs is a good ground.
Howard