case ih 255 fuel shut off solenoid

Discussion in 'Case / Farmall - International Harvester' started by firefighterfox, Nov 12, 2008.

  1. firefighterfox

    firefighterfox New Member

    3
    Nov 12, 2008
    Hello all,
    I am new to the forum and hope I am in the right area to ask this question. If not someone let me know.
    I'm working on my neighbors case IH 255 tractor. The key switch will no longer cut the diesel engine off like it used to. I have 12 volts to one of the two wires that connect to the fuel shut off solenoid and I am assuming that the other wire goes to ground when the key is placed in the off position. If I ground the wire coming out of the solenoid it will work just fine. I don't have a schematic and I'm not shure how this is accomplished when the key is turned off.
    Anyone out there familiar with the problem or the fix?
    thanks for any help,
    firefighterfox
     
  2. chrpmaster

    chrpmaster New Member

    May 5, 2004
    First of all Welcome to the Tractor Forum!

    Have you tried to trace the wire back to ground? It sounds like you just have a broken wire and need to replace it. If you do than make sure you also clean where the wire attaches to the frame.

    You could just run a new wire to the frame if you can't find or get to the original site. All you need is a place to ground out the ignition.

    Andy
     

  3. firefighterfox

    firefighterfox New Member

    3
    Nov 12, 2008
    I can groud it out but then the solenoid stays engaged 24-7. I don't know how it is accomplished, but somehow the grounding of the solenoid (energized/activated fuel cut off) occurs when the key is turned off but only long enough to kill the engine, then the solenoid grounding circut is opened, allowing the solenoid to relax to the open fuel position. I have not exposed the wire from the solenoid to it's completed path. I'm thinking there must be some type of component in that grounding circut that switches the grounding circut on and off?
    any ideas about how this is done?
    thanks,
    firefighterfox
     
  4. Morgan

    Morgan New Member

    528
    Oct 26, 2006
    The solenoid should stay off until the key is switched to the on Position. Its natural position should be OFF. Thats the way it is on the diesels I work on at work. The power should open the solenoid and lack of power should be off.
     
  5. firefighterfox

    firefighterfox New Member

    3
    Nov 12, 2008
    Thanks for the reply.
    When I disconnect the two wires to the solenoid, one has 12 volts on it 24-7 ( key on or key off ). The other other wire has no voltage and when I ohm it out it does not go to ground ( key on or key off ). With the two solenoid wires connected the solenoid will not engage ( key on or key off ). I can manually ground the no voltage wire of the solenoid and it will engage and kill the engine but it will continue to stay energized until I remove the ground connection. That grounding wire does not return to the key switch. ( not by color code or size anyway )
    If the grounding wire is not removed then the solenoid will stay energized 24-7 ( key on or key off ) which would run the battery down and/or burn up the solenoid.
    thanks again for your help,
    firefighterfox
     
  6. smithgd

    smithgd New Member

    1
    May 28, 2010
    I was curious if you ever resolved your problem. I currently have a MF 481 that won't shut down and there is always constant voltage to the fuel shut off solenoid.
     
  7. Norskie

    Norskie New Member

    1
    Jun 29, 2016
    Does anyone have an answer to the original question? I have the same problem on my Case IH 255.