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Electoral issues...need help fast!

posted by  AlanS on  Sat Jun 29 12:04 CST 2024
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last visit: Sat Oct 4 19:59 CST 2014
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2006 xc70. I put new LED bulbs in last year- everything was great till last nite. Driving home, I noticed the lights were dim...upon arriving home, the lights were no brighter than an old flashlight... Revving the car does not increase the brightness. What should I explore? What is the voltage that I should expect from the battery at its terminals? What is the voltage I should expect at the headlight sockets? I will try to look around for any 'loose' connections...Don't know what else to do? My local mechanic is off for 2 weeks, I'm afraid to drive too far from home. Alternator?








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    Electoral issues...need help fast!

    posted by  machine man on  Sat Jun 29 20:20 CST 2024
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    last visit: Wed Oct 22 15:40 CST 2014
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    Hi,

    Check for a bad ground connection as that is what affects headlights to become dim.
    Especially if it’s only one of them but you are saying that is was both of them. Still a common ground in point could be the issue.

    The chances of both lamps, even LEDs, shouldn’t do that IMHO.

    PHIL








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    Electoral issues...need help fast!

    posted by  Robert S. on  Sat Jun 29 14:44 CST 2024
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    last visit: Sun Sep 21 05:48 CST 2014
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    Likely it's not the LED lamps causing the issue. Is the Red dash warning light illuminated for Battery?

    First guess would be a No Charging condition from the alternator. Had a similar scenario a while back. The voltage regulator (it's a module inside the alternator) had failed due to worn voltage regulator brushes. Removed old original voltage regulator, installed new Bosch voltage regulator. Charging was restored and alternator checked out OK.

    BB's advice still applies; check VDC measurements at the battery.








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      Electoral issues...need help fast!

      posted by  AlanS on  Sat Jun 29 15:23 CST 2024
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      last visit: Sat Oct 4 19:59 CST 2014
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      12.5v engine off, 14.5v engine on. 12v at headlight socket. Can led bulbs be checked out if the car directly connected to the battery? That would eliminate the whole system anddtell me if the bulb has degraded.








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        Electoral issues...need help fast!

        posted by  B.B. on  Sat Jun 29 22:20 CST 2024
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        last visit: Mon Oct 6 13:15 CST 2014
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        Hi Alan,

        >12.5v engine off, should be 12.6

        >14.5v engine on. Too High-
        Should be 14.0v
        You'll be losing filament bulbs fast, and over charging the battery.
        A voltage regulator issue- see if the brushes are worn out first.
        Check the D+ wire to the alternator for a solid connection
        If you can, check the level in each battery cell

        >12v at headlight socket. Low
        Maybe croaked LEDs, are those fanless (short life) LEDs?
        If they have fans , see if they are working, if they quit the LED's will
        overheat and shut down.

        Hard to diagnose without the wiring diagram. How do folks do it?
        Please provide a link to the Volvo wiring diagram for your car,
        which is the #1 tool you need to troubleshoot wiring.

        >Can led bulbs be checked out if the car directly connected to the battery?
        No problem, LEDs run on a wide voltage input.
        LED drivers include a DC to DC converter and LEDs run at a lower voltage.

        DON'T LOOK AT AN LED HEADLIGHT WITHOUT WELDING GLASSES!

        Cheers, Bill








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        Electoral issues...need help fast!

        posted by  Robert S. on  Sat Jun 29 15:56 CST 2024
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        last visit: Sun Sep 21 05:48 CST 2014
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        Those are good readings at battery and sockets.

        Try swapping back to the original bulbs? Hopefully you’ll get your lights back.

        Yes bulbs can usually be tested with isolated / independent power supply.








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    Electoral issues...need help fast!

    posted by  B.B. on  Sat Jun 29 13:58 CST 2024
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    last visit: Mon Oct 6 13:15 CST 2014
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    Hi Alan,

    With the car off you should get 12.6 VDC at the battery anodes.
    With the car running you should see about 14.0 VDC at the battery.

    Maybe there's a headlight relay, but I don't have the wiring diagram?

    Bill







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