12v Gauge Problem

Discussion in '1947-1954' started by thecramp, Oct 21, 2008.

  1. thecramp

    thecramp Member

    Joined:
    Apr 2, 2008
    Messages:
    27
    Hi, i just buy a new 12 V Gauge Cluter, and my problem is that when i plug it the battery and fuel needles are going directely to the maximum value at the right, does it hapened to one of you ?

    Thanks
     
  2. Wolf

    Wolf Member

    Joined:
    Apr 20, 2008
    Messages:
    888
    Location:
    Kansas
    mine did that also, but it was the old gauge. tracing it back i found that my sending unit was well... completely gone, thus causing a short circuit or incomplete circuit. I searched this forum and also http://www.oldgmctrucks.com/
    discussion boards for fuel gauge or sending unit problems. I wish i would have kept those pages, but i didn't. However there is a few step by step procedures that will pinpoint if the problem is the sending unit, the wire between the sending unit and gauge or the gauge. Also search for a wiring diagram for your truck. Here is a link for mine. http://www.oldgmctrucks.com/photos/GMCWIRE_AllModels.jpg
    It is a 52 GMC 3/4 ton, which where originally 6Volt + ground electrical systems. i just followed the diagram, and changed polarity and added a voltage reducer to get my gauge to work with the 12V - ground system I have now.

    If I find the pages that I used, I will send you the link. It could very easily be a short in the wire going back to the tank. I found 3 bare spots in mine. :eek:

    Best of luck
     
    Last edited: Oct 21, 2008
  3. thecramp

    thecramp Member

    Joined:
    Apr 2, 2008
    Messages:
    27
    oki thanks ; it's Strange because everything seems to be ok, i didn't see problem before, my sender unit is new and my gauge too. i 'll try again to examin all wire and plug, i think my ground is good too :-( Thanks , i 'll tell you when i'll find.
     
    Last edited: Oct 22, 2008
  4. vwnate1

    vwnate1 Member

    Joined:
    Jan 1, 2000
    Messages:
    11,666
    Location:
    AMERICA !
    Gauge Faults

    Please do a search for my older posts on gause testing . I wrote comprehensive step by step directions , do them in the correct order and you'll soon know what's what .

    DON'T let the <magic> smoke out of the wires ! :eek:
     
  5. thecramp

    thecramp Member

    Joined:
    Apr 2, 2008
    Messages:
    27
    i'll do the research, ok there is maybe a problem with the wiring with the fuel gauge , but what is really strange it's the battery, the needle goes to the maximum, the voltmeter for battery is very simple to plug, but it react as a 6V , the stranger is that it's written 12v on the back! , i don't understand , how can i test if it's really a 6v ? where does the needle should stay in the good position ?

    Thanks.
     
  6. vwnate1

    vwnate1 Member

    Joined:
    Jan 1, 2000
    Messages:
    11,666
    Location:
    AMERICA !
    O.K. here's the basics :

    power to the _left_ most post , other post no connection , the gauge should high side .

    Now , ground the rightmost post (the sender side) and the gauge should go to empty .

    This and more was in my other post , I'm not trying to shine you on , I'm recovering from a traffic accident.
     
  7. LOUDEMRILK64

    LOUDEMRILK64 Member

    Joined:
    Sep 19, 2005
    Messages:
    58
    Location:
    TERRE HAUTE
    I am going through the same thing right now myself. Figured it was just a bad gauge so I just ordered another before i saw this post. Let me know what you find out also
     
  8. Wolf

    Wolf Member

    Joined:
    Apr 20, 2008
    Messages:
    888
    Location:
    Kansas
    Im sure Nate's post was the one that I found that went though step by step on what to look for and what is wrong. Helped me find what was wrong on mine real quick.

    there is really only 3 things, sending unit, wire from sending unit to gauge, or gauge. and make sure you have a good ground.
     
  9. vwnate1

    vwnate1 Member

    Joined:
    Jan 1, 2000
    Messages:
    11,666
    Location:
    AMERICA !
    Thanx Wolf !

    That's the one , could you maybe please post up a link to it ? .

    IIRC it was titled " Fuel Gauge Diagnosis " or similar .

    You are correct , there's only a very few things that go wrong ,take your time and ensure good power and perfect grounds to both gauge head and sender , it'll work fine for pennies .
     
  10. Larrys 48

    Larrys 48 Member

    Joined:
    Dec 7, 2007
    Messages:
    617
    Location:
    Spokane, WA
  11. vwnate1

    vwnate1 Member

    Joined:
    Jan 1, 2000
    Messages:
    11,666
    Location:
    AMERICA !
    Thanx !

    That one is close , I am pretty sure a while ago I wrote one that covers everything step by step in one long(ish) post...

    If this one gets the job done , well and good .
     
  12. Wolf

    Wolf Member

    Joined:
    Apr 20, 2008
    Messages:
    888
    Location:
    Kansas
    YEP that is the info that I used. by the way thanks nate for posting it!! :D
     
  13. jef5150

    jef5150 Member

    Joined:
    Oct 13, 2008
    Messages:
    17
    Location:
    Calaveras County,Calif
    Just a thought (possibly have this backwards :confused:)..,if your new sending unit is a 0-90 ohm and your gauge is a 0-30 ohm your gauge will read "full"

    jeff
     
  14. Greg_H

    Greg_H Member

    Joined:
    Oct 7, 2006
    Messages:
    112
    If the line that goes to the sending unit is open, it will read full and in a hurry.
     
  15. LOUDEMRILK64

    LOUDEMRILK64 Member

    Joined:
    Sep 19, 2005
    Messages:
    58
    Location:
    TERRE HAUTE
    I just replaced my fuel gauge and everything works fine now
     
  16. thecramp

    thecramp Member

    Joined:
    Apr 2, 2008
    Messages:
    27
    ... i 'm back , i'll follow the link and test the fuel gauge later, i'm actually concentrate on the 12 v gauge, the problem is the same, i pluged a wire on the body (ground) and an other on a 12v wire, the needle still go the the maximum on the right (if i invert wire it's on the left), i tried to wait a seconde to see and my fuse burned ( can it be a short circuit with 2 wire to plug?). What do you think it can be, i have only 2 wire a ground and a +12v and the gauge, it doesn't work ! crasy no? somebody can send me a picture to see how the needle should be with the 12 volt in the gauge . thank tou much.
     
    Last edited: Nov 12, 2008
  17. vwnate1

    vwnate1 Member

    Joined:
    Jan 1, 2000
    Messages:
    11,666
    Location:
    AMERICA !
    You're all Over The Map

    And this makes helping you near impossible as you're probably vreating more problems as you jump from one thing to the next .

    Now , go get a multi-meter and set the range on 20 Volts DC , see what the voltage is at rest and when the engine is running...
     

Share This Page