Help on tracking a wiring problem

Discussion in 'Technical' started by TUK101, Mar 3, 2009.

  1. TUK101

    TUK101 Member

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    I have a 72 Maverick 4 door and whenever I turn the lights on, it blows the fuse to the dash lights. I don't have my wiring schematic yet, so I am asking you guys for some pointers on tracking this problem down. I have only had the car for about 5 days now and I have checked the stereo, but it is wired back into the old harness. I even unhooked it and tried the lights but it still burnt the fuse. Now the headlights and all that still stays on, turn signals work. It just blows the 4 amp fuse to the dash lights. What else is on that circuit that could be causing this problem?
     
  2. rayzorsharp

    rayzorsharp I "AM" a Maverick!

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    I still bet the problem is in the stereo. Try unhooking ths stereo all the way including removing the ground wire.
     
  3. random hero

    random hero 1972 ford maverick I6

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    check for a short to ground before the load(dash lights) thats the only thing i can think of, maybe the power wire was rubbing. maybe someone put higher amperage bulbs in the dash and it snaps the 4 apm fuse...which isn't much. just 2 screws to get the cluster out...hope this helped...and welcome to the forum :Welcome:
     
  4. ratio411

    ratio411 Member

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    I'd be looking for a dead short myself.
    You say the radio is wired into that circuit?
    If ONLY the radio lights are wired into that circuit, then fine, but if the radio is drawing all of it's power from that circuit, then it is overloaded. You could have a short inside the light switch itself. Those switches go bad fairly regularly.
    It is an over the counter part at the local parts house if that is the problem.

    When the dash lights blow, does it take out your interior light too?
     
  5. Bryant

    Bryant forgot more than learned

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    there is probly a light wire that is disconected and touching some metal. some cars had a lighted ash tray. there was a light wire that went to the stock stereo that could have been left loose after the aftermarket stereo install and is grounding out. i belive the wire color for dash lights is light blue with a read tracer stripe. start looking around under the dash for any loose wire with the ends touching someting metal.
     
  6. TUK101

    TUK101 Member

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    I have already tried unhooking the stereo completely and it still blows that fuse. I even tried a 10 amp fuse (since thats the only size that either Napa or Autozone carries in that length of fuse that they had in stock). It still blows it, and it is intant. So I am sure that a + wire is grounded to some metal somwhere, I was just hoping that one of you had maybe had a similar problem and could point me in the right direction. Since I dont have a wiring schematic I am not quite sure which branch of wires that I am searching for is all. I am foreseeing haveing to remove half the dash to find it lol.
     
  7. maverick1970

    maverick1970 MCG State Rep

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  8. TUK101

    TUK101 Member

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    Thanks a ton. That should help.
     
  9. Bryant

    Bryant forgot more than learned

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    i have see bulbs fail and short out internaly and cause fuse problems
     
  10. TUK101

    TUK101 Member

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    I totally took the dash out and tried turning the lights on and it still blew the fuse. What else is on the circuit that could be blowing the fuse? Could it be the light switch itself that is causing it? I checked wiring as best I could and couldn't find anything with open ends or where it may have rubbed. I looked at the schematic, but I guess that I am not smart enough to read it lol. It is obviously something after the switch, so I guess I will try and look at the schematic again.
     
  11. rthomas771

    rthomas771 Member

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    Here ya go
     

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  12. rayzorsharp

    rayzorsharp I "AM" a Maverick!

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    Is the radio still attached to the dash? If so, is the black ground wire of the radio tied to any of the factory wires to get a ground?
    The reason I ask is because I recently had to find a short for a friend in his 71 Maverick. A stereo shop had installed his radio and it was blowing the same fuse. I could unplug the radio harness but it did not go away. The short finally went away when I totally removed the complete radio from the dash. Came to find out the stereo shop used the light blue wire/red stripe to tie the ground wire into. When the radio was bolted to the dash, instant short. Just something to look at.
    If that's not it, then you still need to look at this blue/red wire (goes to several locations for different lamps) and make sure it is not getting grounded out anywhere. A volt meter can be helpful here.
     
  13. TUK101

    TUK101 Member

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    rayzorsharp, you rock. Thank you all very much. The ground wire was indeed grounded to the blue/red wire and was blowing the fuse. After reading the schematic earlier and then reading rayzors post above this I got the lights working. Tomorrow I will fix the speedometer and everything will be functioning as it should. Again, thank you all very much for the help.
     
  14. rayzorsharp

    rayzorsharp I "AM" a Maverick!

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    Cool! Glad to be able to help. :Handshake
     
  15. MavMark

    MavMark Mega Modifier

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    Heh, you beat me to the answer, Ray. :) I was gonna mention that the blue wire with the red stripe was part of the original wiring harness and one time I had the same problem when that particular wire had been cut all the way back to the connector, but one single strand of copper wire remained sticking out and it would occasionally touch the outer case of the stereo I had installed...
     

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