Headlight issue

Discussion in 'Electrical Systems' started by Shruted It, Sep 2, 2018.

  1. Shruted It

    Shruted It New Member

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    Hey All,

    So interesting HL issue Im having and hoping for some help. On my '72 camaro, HL didnt work but parking lights, tail, brake lights, etc worked. After a quick look, I discovered the dimmer switch was completely broken in 2 pieces. I swapped for a new dimmer switch and the HL issue was solved....so I thought.

    My first drive a night, I realized that only highbeams worked and nothing for the low. When idling for about a minute, the HLs start flickering off and on. If I turn the HLs off by the switch, and turn the HLs back on they stay lit and solid for about 30 seconds before beginning the flicking issue again.

    Ive rechecked the connections at both the dimmer and the HL switch and all appears to be good. Not sure what's causing my issue.

    Any ideas?
     
  2. Gary S

    Gary S Administrator Lifetime Gold Member

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    Any time either high beam or low beam only works, the problem has to be in the dimmer switch or the wiring from the dimmer switch to the bulbs, or the bulbs themselves. You can easily check the dimmer switch with a voltmeter by pulling it off the floor, and you can also check for power at the bulbs with the voltmeter. That should tell you where your problem is.
    The fact that you can't get low beam working at all and high beam only part time says that your problem could be even before the dimmer switch, but you should also be able to determine that by measuring voltage at the dimmer switch.
     
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  3. xten

    xten Veteran Member

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    Clean the contacts @ the H/L bulb and in the plug too. They get corroded, and lose contact. Common problem. Try that first. Easy, and free.
     
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  4. Jim Streib

    Jim Streib https://www.flickr.com/photos/121766713@N04/albums

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    Yep, time to break out a meter and see what is going on at different test points.

    Also don't forget the grounds. Normally each side of the headlights ground to a bolt or screw onto the radiator support which might only affect one side if the ground is poor but if the radiator support is not grounded well to the fenders and firewall, you can have issues with both sides.

    Also too, check what kind of headlights you have as maybe the switch is becoming overloaded or if it has a circuit breaker built into the switch maybe this is flaking out.

    This might help too with tests for power and ground:



    Jim
     
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  5. Shruted It

    Shruted It New Member

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    Thanks for all of the advice. I've gone through with a meter testing different points. HL switch to dimmer gets 12v. At the HLs i appear to be getting 12v for each wire (hi and low). The only issue obvious to me is that the ground wire on one HL is not securely clipped into the HL plug. As i push the clip onto the HL, the ground gets push back.

    I've played with the ground going into the plug to secure it but its still a little hit or miss.

    For what ts worth, I dont believe this one ground would cause the failing of both low beams as well as the blinking high beams would it?

    Thanks all
     
  6. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

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    No... One headlight ground won't affect both, directly.
    But a poor ground will cause higher resistance and potentially heat up the switch to trigger the breaker for both.
     
  7. Shruted It

    Shruted It New Member

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    Interesting.. I should get the troubled ground plug properly secured b/c either way its an issue. From their, it'll be a process of elimination until the problem is solved.

    Appreciate the input.
     
  8. Shruted It

    Shruted It New Member

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    Hey all,
    Just some updates. Going along the headlight wiring with a voltmeter I was getting 12 volts along the whole path. Still however no low beams worked and the high beams would come on but then after about 30 seconds they would start blinking off and on. I inspected the headlight bulbs themselves and discovered that the driver side headlight had a prong that was loose. It was loose enough that it actually broke inside the headlight wiring clip. I picked up a new headlight plugged it in and as of now I have low beams working and they seem to be steady. The high beams however still give me the same blinking off and on

    To me even if the headlight bulb had a loose prong that wasn't making good connection, it doesn't seem that would cause both headlight low beams to not work. Does that sound strange or an expected side effect given this information?

    I have a new HL switch ordered in case thata the culprit for the blinking high beams. There is already a brand new dimmer installed

    Thanks all!!
     
  9. Shruted It

    Shruted It New Member

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    *update*

    New headlights, new HL switch and new dimmer has solved all issues with the HLs. I now have fully functioning low beam and hi beam that no longer flicker.

    Thanks all for the input and advice on my issue.

    Thanks!!
     

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