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Headlight fuse pops when I "get on it"

Discussion in 'The Hokey Ass Message Board' started by DaddyO's..Deuce, May 19, 2013.

  1. chaddilac
    Joined: Mar 21, 2006
    Posts: 13,866

    chaddilac
    Member

    You can see two holes in the one on the left... so they are probably grounded through the mount and headlight bar.

    I suspect either you have a wire that gets in a bind and shorts out, or when you rev it, too much juice goes through the system and blows the headlight fuse.
     
  2. pottsie454
    Joined: Feb 12, 2011
    Posts: 399

    pottsie454
    Member

    I'd guess a chassis/frame ground. But that out mean that the light itself needs to be ground get to the headlight housing to work properly.
     
  3. Mr48chev
    Joined: Dec 28, 2007
    Posts: 28,363

    Mr48chev
    ALLIANCE MEMBER

    Well you can figure out who actually knows something about automotive electricity and who throws out something they overheard down at the gas station in this type of thread.


    1. An alternator overcharging will not blow a fuse but it could blow the filaments in headlight and other bulbs over a period of time. This is why guys running 8 volt batteries on six volt systems go though head light bulbs a lot sooner than they should.
    Fuses blow because there is an excess load being put on them and not because there is too much voltage being pushed at them.

    2. being that it is a load situation and only happens when you "get on it hard" I'd have to go with those who say that there is a suspect connection in the wiring somewhere.
    Somewhere along the line there is a wire going through metal that has a bare spot that only comes in contact with the metal when you get on it and the wire is pulled into contact with the metal. If the headlight harness and engine harness go through the same spot in the firewall that is where I'd look. Or on the inside of the firewall where the headlight wire may be pulled into contact with metal.

    3. On the motor mounts, those 58 Impala style mounts have always broken when they get a bit of age on them an you get on it hard. The simple fix is the replacement mount with the tab that keeps it from lifting too far but it is a bit ugly. Solid mounts aren't that spendy though and you can always change them back if you don't like them.
     
  4. chaddilac
    Joined: Mar 21, 2006
    Posts: 13,866

    chaddilac
    Member


    What happens when a wire is shorted to ground, too much juice and more than the fuse can handle, isn't that correct?
     
  5. langy
    Joined: Apr 27, 2006
    Posts: 5,735

    langy
    Member Emeritus

    Amps kill fuses not volts
     
  6. DaddyO's..Deuce
    Joined: Jul 31, 2011
    Posts: 782

    DaddyO's..Deuce
    Member
    from Missery

    Okay, not to further complicate things BUT... here is the starter I ran on my old engine combo [​IMG] now on my new starter which is a dual post compared to the old single post, I had this purple wire. It was attached to the old starter, not sure what it's purpose was (can you tell I'm not the one who wired this car?) Anyway when hooked up to the new starter it caused my starter to stay engaged. Took me two starters to figure that one out. So with it disconnected every thing seemed to function okay....except the headlight ordeal. [​IMG] now notice that this purple wire runs to the fusebox. It runs right to the fuse that blows and causes the headlights to go out. [​IMG] ideas?????
     
  7. langy
    Joined: Apr 27, 2006
    Posts: 5,735

    langy
    Member Emeritus

    Not sure what wiring kit you have but most wiring kits have a wire that supplys 12v to the coil when the key is engaged in the start position, the other tag on the solenoid is the start wire, do you have them round the wrong a way ?
     
  8. langy
    Joined: Apr 27, 2006
    Posts: 5,735

    langy
    Member Emeritus

    Just reread and do you mean the purple wire was just hanging and not connected ? if so when you get on it i would think its hitting a ground and shorting the fuse
     
  9. F-ONE
    Joined: Mar 27, 2008
    Posts: 2,497

    F-ONE
    Member
    from Alabama

    OK, Here goes my two cents,

    On most factory cars of that era the headlights were not fused. Most went through a circuit breaker or sometimes they were straight wired.

    Another factor could be the size wire used in the lighting system. Since these lights are 1934 commercial lights I would run them on a heavier gauge through a circuit breaker. Too small a gauge " 12 volt wire" may or will cause the wire to overheat, popping the fuse.

    Ever notice how lights get brighter when you rev a car? If too small a gauge is used they may be overheating, thus popping the fuse when you rev.

    As always check or install good grounds.

    One more thing....

    Run a dimmer switch so you can have high and low beams.
     
    Last edited: May 19, 2013
  10. F-ONE
    Joined: Mar 27, 2008
    Posts: 2,497

    F-ONE
    Member
    from Alabama

    [​IMG]
    My next big thing is rewiring my F1. I'm going to have to fix a re wire that's just a few years old, the reason the BS modern crimp connectors. They come loose. I'm going to have to replace/re-do them all.

    Cut the blue off of them and solder them in, they're trouble crimped.

    That stuff is made for lawn mowers not cars....been there, redoing that.;)

    [​IMG]
     
  11. DaddyO's..Deuce
    Joined: Jul 31, 2011
    Posts: 782

    DaddyO's..Deuce
    Member
    from Missery

    I had the purple wire taped up and in the wire loom so it wasn't touching anything. the headlights are repops with modern wiring. The brown wire is the one coming off the back of ignition switch when turned to the "start" position, big red wire from battery, one of the small reds is off the other side of ignition switch for "on" position, trying to remember the other smaller red was to alternator maybe. but what the heck was this purple wire was for? Goes straight from starter to this fuse...
     
  12. Buy yourself a book on rewiring and start over fresh...Looks like one hell of a mess to me..
     
  13. DaddyO's..Deuce
    Joined: Jul 31, 2011
    Posts: 782

    DaddyO's..Deuce
    Member
    from Missery

    ^^^^^ that's not happening, never had a single wiring related issue with this car for the last 7-8 years until installing these headlights/starter. I just think this mystery purple wire is the culprit. I'll figure it out, not the prettiest wiring job no, but it's not all that bad either.
     
  14. pottsie454
    Joined: Feb 12, 2011
    Posts: 399

    pottsie454
    Member

    Just for shits and giggles check to see if your altenator is outputting an ac current, that will also cause all kinds of havoc. This is just coming from a guy who heard it from a gas station attended. Lol, no offense taken just making jokes.
     
  15. DaddyO's..Deuce
    Joined: Jul 31, 2011
    Posts: 782

    DaddyO's..Deuce
    Member
    from Missery

    Going to put a different end on the purple wire, hook it up to the main starter post. Thinking that was where the main juice for the headlights was coming from. Maybe it's trying to draw to much juice through a smaller wire and killing the fuse????? Worth a try anyway. Can't do much testing until I get the motor mount fixed, thanks to all that replied. I'll let you know what happens.
     
  16. the purple wire should have gone to the coil. it was powered [by the starter when the starter was engaged, and supplied 12 volts to the coil, bypassing the resistor or resistor wire. with a gm hei ignition it is not necessary. are you sure it goes to that fuse?
    your lighting system should be very simple, having no dimmer, it should be power to the headlight switch and a wire to ONE of the headlight filaments and the socket should be grounded. any loose connection or bare wire will blow the smaller fuse. overcharging would not, the normal load of the bulbs are not going to draw more amps.
     
  17. test the purple wire for voltage at both ends and/or try to determine if they are the same wire. also with a test light try to find out were the headlights get their power from. it should be fused, and powered all the time [not keyed]
     
  18. DaddyO's..Deuce
    Joined: Jul 31, 2011
    Posts: 782

    DaddyO's..Deuce
    Member
    from Missery

    Sounds like good advise, I'll check it out tomorrow thanks.
     
  19. I was just chasing wires on my truck and installing a new E-Z wire kit and what "tb33"is saying seems to be EXACTLY what they talk about for this same reasons in their install manual , between that and checking for shorts you should be in biz .
     
  20. donsz
    Joined: Nov 23, 2010
    Posts: 211

    donsz
    Member

    Some quick thoughts:
    1. From the photo of the headlight switch, the green wire on the right side looks like it is close to another terminal on the switch as it goes back. Also the insulation around the crimp looks a little suspect.
    2. Doesn't look like it here, but some headlight switches/control devices had bi-metallic current sensors built in, that acted like a fuse. Doesn't look like you have any such device from what I have seen, but just in case...
    don
     
  21. lippy
    Joined: Sep 27, 2006
    Posts: 5,363

    lippy
    Member
    from Ks

    Don't get on it, your too heavy for that fuse.:D
     
  22. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 5,409

    Ebbsspeed
    ALLIANCE MEMBER

    Yes, we certainly can.


    An alternator overcharging (higher voltage) will cause the current through the headlights and associated switches, fuses and wiring to increase. Headlights, to a point, will tolerate increased voltage across the filament, or current through it, fuses not so much, especially those that are running on the hairy edge of their current rating.

    http://www.electronics-tutorials.ws/dccircuits/dcp_2.html
     
  23.  
  24. terryble
    Joined: Sep 25, 2008
    Posts: 541

    terryble
    Member
    from canada

    I will admit I did not read all the answers given here but I would check all your grounds I remember a car I had and if you missed a shift at high RPM it would blow the taillight fuse. It drove me crazy but finally fixed all the taillight grounds and cured the problem.
     
  25. d2_willys
    Joined: Sep 8, 2007
    Posts: 4,146

    d2_willys
    Member
    from Kansas

    Get some "Gravedigger" headlights and wire them up for the high RPMS.

    I would check the charging system as someone has already pointed out.

    After that the flux capacitor suggestion sounds like another idea. LOL
     
    Last edited: May 22, 2013
  26. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 5,409

    Ebbsspeed
    ALLIANCE MEMBER

     
  27. DaddyO's..Deuce
    Joined: Jul 31, 2011
    Posts: 782

    DaddyO's..Deuce
    Member
    from Missery

    Man, this is getting complicated :confused:
     
  28. Mr48chev
    Joined: Dec 28, 2007
    Posts: 28,363

    Mr48chev
    ALLIANCE MEMBER

     
  29. using ohms law, the resistance [the bulb] stays the same. the voltage goes up, the resistance at the fuse Has to drop.
    example; when you convert a 6 volt system to 12 volts you do not need to increase wire size.
    marginal fuse or not...
     
    Last edited: May 21, 2013
  30. nukeman
    Joined: Mar 17, 2007
    Posts: 131

    nukeman
    Member
    from Michigan


    Your first sentence contradicts your second sentence. The resistance does remain the same, but in the water flowing in a pipe analogy, at a higher voltage, (electrical pressure) more amps get pushed past the resistance. The resistance doesn't drop.

    [​IMG]

    Now, when you convert from a 6 volt system to a 12 volt system, you replace the low resistance 6 volt bulbs with higher resistance 12 volt bulbs so that the wattage remains the same. (wattage is power and in a simple circuit is volts times amps.) You can keep the same wire size, but you have to change the resistance of the bulbs or you'll have problems.

    [​IMG]
     

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