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Ladies and gents if this makes any sense,
I have no power to the headlights when I pull the switch, the switch works as far as continuity is concerned and the vacuum works perfectly.
I replaced the ignition switch to no avail
Taillights and turn signals work perfectly
The headlight circuit works fine when I connect a 12volt source to the (yellow) headlight wire in the harness, anyone know what could be wrong?
Well. I would have to ask if all the wiring on the car is stock standard, or has someone added relays for the headlights. If not it's a very good and common upgrade.
Do you own this book for your model year? If not get one. They make the wiring look very simple.
Start with a test light. Do you have power to the headlight switch, (do the marker lights and tail lights light up). Do you have power up to the high/low switch? Do you have power out of the high low switch? And then through the bulkhead connector into the engine compartment.
no I don't know what it is. But if your tail lights are lighting up, I would likely start at the high/low switch.
The tail lights light up and when you wire a 12volt source into the headlight connection (yellow wire on the switch plug) the head lights turn on and the high beam switch works. As far as I know everything is original.
Power distribution page from 77 wiring manual. Power to the headlights is red wire. Note fusible link right off starter solenoid. Then 2 connectors before it makes it's way to the headlight switch. Headlights have power with car off. Replacing ign switch is pissing up a rope.
yeah, the headlights do not come on but the switch does work with the tail lights.
If you connect a 12 volt source to the (yellow wire for the headlights) they will come on and the high/low beams work so it's not a break in the wire
Power comes off the Solenoid. Same post as positive battery cable. There's a fusible link right off the Solenoid. If your not getting power to the back of the headlight switch. Start there. With a test light. Do you have power on the far side of the fusible link? Follow the wire all the way to the headlight switch. Yes somewhere between the Solenoid and the headlight switch you have a blown fusible link or a broken wire or bad connector. You really should get the electrical trouble shooting manual.
Headlights run off of battery power through the headlight switch. Tail lights run power through tail light fuse and through the same switch, yet different circuit's inside the switch. You keep talking about a yellow wire. My car has red for headlight power and orange for taillights. Some minor differences between years. But the switch design is the same
Tail light circuit through switch.
Headlight circuit through switch. Note 2 different switches in one switch. However. You say if you put power to it all works, so you need to follow the power wire back to the source at the starter solenoid and find the break and restore power. If the fusible link has blown. You need to find out why.
Where are you applying power? The input to the light switch (pin 1), or the output from the light switch (pin 6)? There is a circuit breaker INSIDE the headlight switch (shown in the second image in post #9). It is s'posed to reset when cool, but perhaps it did not in your case. It seems that you should be able to test continuity of the switch and see if that's the problem.
Headlight problem
