Question about headlights

Discussion in 'Health and Wellness Forum' started by Cookie, Jan 3, 2012.

  1. Cookie

    Cookie .

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    Attn all motor people,

    If both your headlights go out at the same time, which is it most likely to be, the bulbs or a fuse? Which would you do or check first?

    Thank you.
    :)
  2. Gary in NJ

    Gary in NJ New Member

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    Usually, each light is protected by its own fuse. It would be unusual for both lights or both fuses to fail simultaneously. However, both lights are controlled by a single relay. I would put my money on the relay.
  3. DonL

    DonL Out of the Trades

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    That depends on the Model that you have.

    Could be OP error. lol

    Happy New Year Cookie.
  4. Cookie

    Cookie .

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    Wise guy, it is not OP error, lol.

    The relay is a fuse as well? Will Auto zone put it in you think?

    Happy new year Don. :)

    (this is son's car, so not sure of the model) It is little and red. lol.
    Last edited: Jan 3, 2012
  5. Chad Schloss

    Chad Schloss Member

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    could be a relay. my grandpa drives a 2000 something mercury crown vic. all lights go through a module under the middle of the dash. Module to replace (because they say it is non repairable) is almost $600. I fixed it for $5 bucks after I took it apart and resoldered a relay. This time I used a better relay and remotely located it so it can be replaced if necessary.
  6. Gary in NJ

    Gary in NJ New Member

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    A relay is not a fuse. Usually the relays are located in the engine compartment in a self-contained compartment with a plastic housing. You'll find fuses in there as well. If you look at the inside of that plastic cover it will show you where the relays are located.

    The guys at the local Autozone should be helpful in identifying and replacing the relay.
  7. DonL

    DonL Out of the Trades

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    Auto Z will check it out for free.

    If it is American made depending on the year then the Rear Tail lights may be out also.

    If it is a fuse then there is a reason that it blew.
  8. Chad Schloss

    Chad Schloss Member

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    did he install a radio recently? maybe cut some wires under the dash he wasn't supposed to? lol :) seen that a lot when I used to install car stereos, alarms & car starters when I was younger.
  9. Cookie

    Cookie .

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    I am doing my mom thing. :) I will tell my son about the relay, thank you so very much. I did ask him, about the back lights and he said, they are working, turn signals, the works, just the headlights aren't working. If a fuse, wouldn't a fuse blow just because the fuse went bad? Bad fuse?
  10. Cookie

    Cookie .

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    Oh, boy... you might had hit on something with the radio. I will have to ask him about that one. He only has a small cassette player in this car, and, he wanted a CD player.

    He was talking about installing one.
  11. Cookie

    Cookie .

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    I bet he did.
  12. Cookie

    Cookie .

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    His dad could build a car, a hybrid, better than a car manufactuer. He could fix this in a heart beat. lol.
    Last edited: Jan 3, 2012
  13. Cookie

    Cookie .

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    Nope... he didn't do a radio or CD player, still listening to the cassettes and hating I am sure, every minute of it. :) So, scratch that idea.

    I wish things while I was growing up were different for girls with fixing cars. The interest was not encouraged for it. If I had a daughter, I would really encourage her to take classes in mechanics. At least to do the basics.
    Last edited: Jan 3, 2012
  14. ballvalve

    ballvalve General Engineering Contractor

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    The headlights that I know have to be on a relay that automatically resets, so you get a few more on off cycles of the lights at night so you can get off the road. No fuses for Headlights anymore. Probably a bad relay.
  15. DonL

    DonL Out of the Trades

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    What did he do ?

    He must of had a Girl in the back seat, Smashed a wire from all the bouncing, Blew the fuse, and could not drive home.


    Sounds like a story that my boy would tell, After being out on a date with a Hot Chick.


    Ask her what really happened. She may say, "I just hit the gear shift knob" But she knows what really blew his fuse...
  16. LLigetfa

    LLigetfa DIYer, not in the trades

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    A friend parallel parked his Vette and ran in to grab a pack of cigs. His girlfriend bumped the gear shift knob. The car started to go forward but rather than put the shift lever back in park, she reached across the console and tried to use her hand on the brake pedal. Unfortunately, she hit the gas pedal. Headlights both went out at the same time.

    So we still don't know anything about the car except that it is small and red. Maybe it has those headlights that are always on. Well, almost always... they go off when you pull the hand brake. I had one where the switch on the hand brake lever was out of adjustment and kept the lights from coming on. It was a small car too, but it was more burgundy than red. It had a stick shift and the reverse light switch was also out of adjustment. Whenever I put it in neutral (or was it park?) the reverse lights would come on. People behind me at a red light would freak out thinking I put it in reverse and lean on their horn.
  17. Cookie

    Cookie .

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    I still have a feeling it might be the headlights, the bulbs. Reason being, is, I used to replace mine, both, at the same time, until, a mechanic told me not to do that because, they both could burn out, and, at the time when you need them most. So, I stopped doing that. When, one burns out, I do one... until, the other one burns out. But, it might be also, the relay switch, and, I am sure him and his girlfriend will fix this. Maybe, the older woman he bought this from, did the same thing, I used to do.
  18. nukeman

    nukeman Nuclear Engineer

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    Based on the lack of a CD player, I assume this car is probably pre-early 90's. If that is the case, the headlights may or may not use a relay. Some older cars passed the full headlight current through the headlight switch. The fuse for the headlights will either be in the engine bay or under the dash.

    It would be very unlikely that both bulbs burned out at the same time (even if they were the same age). An overvoltage condition due to a bad regulator in the alternator could cause the bulbs to burn out quickly, but you would also see problems elsewhere (all bulbs burning bright, blowing out early, etc.).

    - fuse
    - relay (if it has one)
    - bad headlight switch
    - bad connection/wiring
    - bad bulbs

    We need a year/make/model to even start to guess what it might actually be. For instance, the ground of the headlights might be shared and often the headlights are on a different circuit compared to the taillights. A bad ground could cause the headlights to flicker or not work at all.

    Start with the fuse as they are cheap and easy to replace. However, as mentioned before, if the fuse is blown, there is a reason. If you just replace the fuse, it may just blow again.

    The older cars without headlight relays also see a more frequent failure of the headlight switch. Since they pass all current through the switch, the arcing, pitting, and carbon buildup can cause the switch to fail. Often, you can open them up and clean the contacts and be good to go again.
  19. cacher_chick

    cacher_chick Test, Don't Guess!

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    It is pretty common for some people to drive around with one headlight burned out and not even notice. They sure as heck do notice when the 2nd bulb burns out though. :)

    Would be good to know what make/model we are working on.

    Do the hi-beams work?
  20. DonL

    DonL Out of the Trades

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    It is OK Cookie,


    You can tell us what Make and Model that he has, even if it is not American made.


    Cacher_Chick has a point.


    The Wallflowers Drove with one Headlight.


    Maybe the Battery is Dead...
    Last edited: Jan 3, 2012
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