84 Caprice, 5.0 - headlights not working on low.

Discussion in 'General Automotive Tech' started by 101Volts, Jan 25, 2016.

  1. 101Volts

    101Volts Well-Known Member

    Joined:
    Jun 11, 2013
    Messages:
    3,016
    Likes Received:
    278
    Trophy Points:
    198
    Wagon Garage:
    1
    Location:
    Pennsylvania
    The headlights all work on high beams, but don't work on low. I already tried using a brand new dimmer switch, that didn't work. So what happened? My manual said a wire or wires have burned out and will need to be replaced.

    This is for the Sedan, though does it matter much between whether it's a Sedan or Wagon?
     
  2. Glide-Aways

    Glide-Aways Well-Known Member

    Joined:
    Sep 21, 2008
    Messages:
    1,442
    Likes Received:
    82
    Trophy Points:
    138
    Wagon Garage:
    2
    Location:
    San Diego
    I'm the farthest thing from an electrician, but do the low beams work off of a separate fuse than the highs? (Could it be just a blown fuse?)
     
  3. joe_padavano

    joe_padavano Well-Known Member

    Joined:
    Feb 9, 2010
    Messages:
    786
    Likes Received:
    135
    Trophy Points:
    117
    Wagon Garage:
    5
    Location:
    Northern VA
    First, there is no fuse in the headlight circuit, there is only a circuit breaker built into the headlight switch.

    Second, the low beam bulbs have TWO filaments, one for high beam and one for low beam. That's why the low beam bulbs have three terminals and the high beam bulbs only have two. Have you verified that both low beam filaments have not burned out? Have you checked for +12v at the low beam terminal at the headlight connector when on low beams? Stop replacing perfectly good parts and start doing some no-cost troubleshooting first.
     
    ModelT1 and Glide-Aways like this.
  4. 101Volts

    101Volts Well-Known Member

    Joined:
    Jun 11, 2013
    Messages:
    3,016
    Likes Received:
    278
    Trophy Points:
    198
    Wagon Garage:
    1
    Location:
    Pennsylvania
    This might end up being a lot simpler than I thought.

    No, Joe; I didn't do any of that. I didn't realize the low beam bulbs have two filaments, I thought it would just be one. Thanks for that, now I have something to check.
     
  5. Silvertwinkiehobo

    Silvertwinkiehobo "Everything that breaks starts with 'F.'"

    Joined:
    Apr 21, 2014
    Messages:
    14,984
    Likes Received:
    2,993
    Trophy Points:
    720
    Location:
    New Braunfels, TX
    Go to Harbor Freight and buy a 12volt test light. This'll make it easier to check for voltage on each connector. When you're ready Google for a headlight diagram. Away you go!
     
    ModelT1 likes this.
  6. peter4821

    peter4821 Well-Known Member

    Joined:
    Apr 17, 2010
    Messages:
    124
    Likes Received:
    33
    Trophy Points:
    56
    Wagon Garage:
    1
    Location:
    DelRay Beach, FL.
    Bet both low beams are out . Been there done that
     
  7. 101Volts

    101Volts Well-Known Member

    Joined:
    Jun 11, 2013
    Messages:
    3,016
    Likes Received:
    278
    Trophy Points:
    198
    Wagon Garage:
    1
    Location:
    Pennsylvania
    Thanks everyone, I've not yet checked the bulbs but they're next on the "To check" list. The car's not being driven in the winter months.
     
    Last edited: Feb 5, 2016
  8. ModelT1

    ModelT1 Still Lost in the 50's

    Joined:
    May 18, 2011
    Messages:
    22,123
    Likes Received:
    1,439
    Trophy Points:
    808
    Wagon Garage:
    1
    Location:
    Central Illinois
    I'd just buy some new and improved bulbs. Make sure the terminals are not corroded while you are there.
    When spring arrives in Pennsylvania, around June 10th, take it for a drive.
     
  9. 101Volts

    101Volts Well-Known Member

    Joined:
    Jun 11, 2013
    Messages:
    3,016
    Likes Received:
    278
    Trophy Points:
    198
    Wagon Garage:
    1
    Location:
    Pennsylvania
    Thanks.

    Actually last year I had it out even in March, the roads were clear then. This year's been pretty mild for winter in my area, though not enough for there to be no deicer on the road. I haven't needed to use the snowblower so far this winter though.
     
  10. ModelT1

    ModelT1 Still Lost in the 50's

    Joined:
    May 18, 2011
    Messages:
    22,123
    Likes Received:
    1,439
    Trophy Points:
    808
    Wagon Garage:
    1
    Location:
    Central Illinois
    Even back in Illinois where we were supposed to be moved they've had very little snow. One son said he doesn't think the ground is frozen very deep.
    I sold my snow blower 22 years ago when we moved to Florida. So far I haven't needed one. It might work for the darn mole hills we have again.
     
  11. 101Volts

    101Volts Well-Known Member

    Joined:
    Jun 11, 2013
    Messages:
    3,016
    Likes Received:
    278
    Trophy Points:
    198
    Wagon Garage:
    1
    Location:
    Pennsylvania
    Update: The headlights were just burned out. Easy fix.
     

Share This Page