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  1. #1

    Default Headlights/running lights not working

    I purchased a 81 full size pickup yesterday, the headlights and running lights aren't working. I checked the headlight switch and im not getting a constant 12v to the switch. I can run a jumper wire from the fuse box to the headlight switch and everything works. Basically I need to figure out how exactly the headlight switch gets its 12 volts if someone can help me with that id appreciate it ?
    Last edited by dpmeeks; 06-07-2013 at 10:03 AM.

  2. #2


    I think you answered your own question... Get they Hayes manuel for the diagram and re-wire the bad boy or find the bad connection and re-solder it. Your lights would be dim with low voltage, they would not stop working.

    The alternator regulates itself, at idol the volts prolly won't read 12 anyways, as the engine speed increses so does the volts the alternator puts out.

    So, as a re-cap; at idol it wont be a steady 12 volts, the alternator regulates itself, your wiring is bad and needs to be fixed, your lights don't need 12 volts to run.
    1998 K1500 Extended Cab Short Bed.
    Z71-HD Chassis-Locker-3.73s-Skid Plates-3rd Door-Transmission Cooler-Tow Package-5.7L

    Oh, you hate your job? Why didn't you say so? There's a support group for that; it's called EVERYBODY. They meet at the local bar.

  3. #3


    Quote Originally Posted by dpmeeks View Post
    Basically I need to figure out how exactly the headlight switch gets its 12 volts if someone can help me with that id appreciate it ?
    This may be a silly question, but it needs to be asked, did you check for a blown fuse?

    '09 Avalanche LTZ - Black
    '05 Envoy XL (sold)

  4. Likes CatastropheADJ liked this post
  5. #4


    There is a relay for headlights, too. Did you check that? If you live near an Autozone, they will put in their tester and check it for free. It can have continuity and still have a bad coil, so the tester is the best way to check them.

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