hobiesailor

So I bought a running 67 mustang, runs great but has some issues as they all do. The big issue right now is no working head lights. When I pull the switch all the way out to the last detent, the tail lights come on and the dash lights come on, no head lights. When i put it to just the running lights (the first detent) the front running lights come on, the dash lights and the tail lights come on. Any suggestions?

69mach1377

Replace the headlight switch or at least remove, clean, check and reinstall it. There may be some bad contacts or loose wires.

musnicki

Also...get a voltmeter and check to see if power is getting to the lights. Check the grounds too.

James

bop11

Here is a diagram of the light switch. For a 67 look at the top A also feeds the horn with a yellow wire. The head lights are not fused but have a circuit breaker in the switch. The power comes out of the switch on H red/yellow and goes to the dimmer. If the dimmer is bad or disconnected no head lights. If other lights work, tail lamps etc. then the breaker is good. The culprit is most likely the foot dimmer.

hobiesailor

So I have replaced both the dimmer switch and the headlight switch, no dice. I'm guessing that it is a ground issue. I have zero idea where the grounds for the headlights are. Any ideas?

69mach1377

Your wiring harness could be fubar...

bop11

The head light ground is the same black wire as the turn indicator and the parking light. So if they work then the ground is not the problem. However, the headlights are grounded to the corner of the alternator regulator and to the point where the alternator grounds to the block. Use a volt meter between the headlamp connector red/black or green/black (high low beam) and the block to insure there is voltage. NOTE: According to the wiring manual, the connectors are not pinned the same for the left and right head light. The left headlight has the black in the center connector pin (not the socket) and the right has it one end plug. Ford has been know to make mistakes in documentation as a close look at the drawing would show the black and green reversed in the left headlight. Make sure the Black goes to the common terminal of the light bulb. You may need to hit the dimmer to toggle between high - low. If you have voltage your problem may be bulb or socket or ground. Check the black wire to block continuity with a voltmeter. You can buy a volt meter at Home Depot for $9.00. If good ground, but no power and the bulb is good (check continuity between black and other leads) check the connector with the red/black, black/yellow and green/black wires. If still no power check the red/yellow wire to the dimmer and on the back of the light switch (pin H) . If no power on pin H of the light switch, buy a new switch