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MM2 Pump not running! Help Please

Discussion in 'Fisher Engineering Discussion' started by killercom, Dec 28, 2012.

  1. killercom

    killercom Junior Member
    Messages: 20

    So yesterday was my first day with a used MM2 that I picked up for $450, decent plow, took care of some minor things. Everything worked fine yesterday, all day. Came back to my house and decided to make a pass in my backyard to my shed. All of a sudden I put the plow down and it stopped moving. No left, right, up or down. Let the plow sit in my heated garage overnight and hooked it up today and still nothing. Red light is on on the joystick, lights work. Truckside wiring is all new except for power cable, solenoid is new, plow side power wire is new. Pump is a 2003 I think, and the negative cable going into the plow is tight but spins a tad like it's stripped into the motor. Any help would be gladly appreciated, I hear we're getting more snow tomorrow and I wouldn't like to miss it.

    Thanks

    Shane
     
  2. brad96z28

    brad96z28 PlowSite.com Addict
    Messages: 1,526

    Do you have power going to the motor? What have you checked so far?
     
  3. rob1325

    rob1325 Senior Member
    Messages: 297

    With test light hooked to negative on truck battery, have someone put plow up, check to see if power going to motor while they are trying to put up. Then put test light on positive on truck battery and probe to negative on electric motor to see if grounded if both light up then electric motor may be bad or that loose connection you talked about on motor is your problem. If test lights don't light up then truck side. Hope this helps
     
  4. brad96z28

    brad96z28 PlowSite.com Addict
    Messages: 1,526

    I have seen bad solenoids light a test light, but not enough power for the plow motor to run lots of times they will let small voltage pass but not enough amperage to make the motor run. Use a head light or something that will draw some amps for a good test.
     
  5. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    Even simpler. Put a voltmeter on the pump.....

    Is the motor ground tight or loose?
     
  6. killercom

    killercom Junior Member
    Messages: 20

    It's loose but worked fine all day yesterday. The ground setup to the motor is threaded in, then theres a bolt then the wire then another bolt if that makes sense. The threads going into the motor are stripped are think making it loose. But I'm going down to figure this all out with a buddy of mine who works on these plows everyday.. I'll post back with a solution if I find one. Any other ideas guys or just focus on that for now?
     
  7. brad96z28

    brad96z28 PlowSite.com Addict
    Messages: 1,526

    A pair of jumper cables work best for me.Rules out alot of bs.
     
    Last edited: Dec 28, 2012
  8. killercom

    killercom Junior Member
    Messages: 20

    The ground connection on the pump is tight and wiggling it did nothing. I heard things that have to do with the crossover relief valves? If I force the plow back to being straight and I try to angle it left is goes right, or would that be bad S1, S2 or S3?? Any ideas guys!? Thanks!!
     
  9. buddymanzpop

    buddymanzpop Senior Member
    Messages: 599

    Do this, place jumper cables to the motor from the battery and let us know if the motor runs.
     
  10. killercom

    killercom Junior Member
    Messages: 20

    The motor does run, the plow just doesn't move
     
  11. buddymanzpop

    buddymanzpop Senior Member
    Messages: 599

    Now check your ground wire at the coils, it's the black/orange wire, it jumps from each of the three coils and then grounds at the (-) stud on the pump motor. Also, make sure your three pin control harness connection at the grill is good. If all that is good I would check the pump inside the resevoir can next.