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I am in the middle of troubleshooting my harness on my ‘61. I have no tail lights, brake lights, courtesy lights and now over the last day or so the headlights don’t come on. I am trying to understand how the headlight switch works.
1) With ignition off & the headlight switch in (Off) - I took a volt meter and read the voltages on top of the connector. I have 12V on the red wire and then rest are 0 Volts.
2) With the ignition still off. I pulled the **** out to the first position - (Parking lights should come on) – I have 12V on the red wire and 12V on the purple wire which goes to the front parking lights – Good! However, no tail lights.
Now my question is - shouldn’t there be 12V on the black wire going to the tail lights? It reads 0 Volts.
As an experiment, I disconnected the battery and ran a jumper wire across the purple and black wires on top of the connector. Repeated step 2 from above and the result is the tail lights came on.
I am trying to understand the functionality of the headlight switch. If anyone has any ideas or know of an article, I would greatly appreciate if you could let me know.
A couple of points:
The brake lights do not go through any part of the headlight switch, so you have at least two problems.
There is no ground on the headlight switch or body of the switch anywhere that affects any of the lights, so I don't know what the red arrow is, unless just to show the cluster itself is grounded.
The answer to your question is, yes you should get 12v on the black wire to the tail lights in both switch positions when you read with the positive meter lead on black wire and meter negative lead on a good ground.
If you are indeed getting 12v on the purple and move the positive lead to the black wire and you are making good contact to it, there is an open contact inside the switch OR on the connector of the black wire.
The rear lights do have a different ground point than the front, so make sure your black/white stripe wire is grounded for the tail, brake, turn signal and license plate lights. The factory ground is in the dash, you can check the rear by grounding any one of the black/white stripe wires to a good ground at the rear. All the lights will come on with the switch in park position if that was your problem. If that cluster ground is not good, you'll lose all the lights in the rear and the courtesy lights. That will not affect your headlights, so you may also have an intermittent dimmer switch on the floor. Work it a few times and see if you get lights in any position.
If in the end, you find out you have your voltmeter on a good ground besides the cluster and you still have zero volts on the black wire at the headlight switch with switch on, it has to be in the switch or connector to it.
Thanks for the message. Sounds like what you have left is a bad headlight switch and brake light switch maybe. Don't forget to check that ground coming from the back, it will kill all the rear lights.
Headlight Switch Functionality
