Headlights with 12V at all three terminals?

[Richard Oben]

In the never ending battle to get 9070 back on the road we are working on the lights. Put the relay kit and replaced every bulb in the car.

Turn on the marker lights and they are great, rear side, front side and front.

Nothing on the headlights. I can ground one of the wires at the turn signal switch/dimmer and they will come on. But if check the wiring that the bulb would plug into on the driver side (either side actually) I get 12v at all three pins.

We swapped the dimmer and the combination switch (which fixed the wipers) and still no headlights.

I have searched and found a lot of stuff but when we check coninutiy everything checks out.

First where are all the grounds on this car, I have a diagram but am not sure if it has all of them listed.

We are afraid somehting is getting power that should be grounded.

Thanks in advance for the help. Richard.

[Richard Oben]

So what are the odds. Three headlight switches and only one worked. BUT they work and on the relays. YEA. Richard.

[SteveJ]

Did you have both bulbs out when you checked voltage? If not, you're probably backfeeding through the circuit, especially if you've lost the ground.

For your vintage car:

The positive side of the circuit goes through fuses (right and left) an on to the headlight. There are two negative wires: one for high beams and the other for low beams. The high beam wires join together to go back to the turn signal switch, and the low beam wires do the same. At the turn signal switch (if your contacts are good) the switch will complete the circuit for either the high beam or low beam. The wire then goes over to the combo switch on the other side of the steering column. When you turn on the headlights, the circuit is completed to ground. You can trace the circuit with an ohmmeter to ensure you have low resistance to ground.

[SteveJ]

Oh sure, I take too long to answer, and you figure it out yourself. :-P

[Richard Oben]

Thanks for the help, it is appreciated. Got to love eBay switches, supposed to work and of course did not. Cheers Richard.

[Zs-ondabrain]

Richard, got your email and responded. Let me know hat ya think.

And don't worry if somethings broke, I got 75+ pounds of switches and switch parts. I gotcha taken care of.

Dave

[Richard Oben]

Box of parts and check on the way, Richard.