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fisher mm plow help?

Discussion in 'Truck & Equipment Repair' started by Ziob34, Feb 16, 2009.

  1. Ziob34

    Ziob34 Senior Member
    Messages: 182

    i have an older fisher mm plow on my 97 ford. recently the pump started acting up.
    when i pick the plow up and let off sometimes i can here the motor/pump still running even though i've let off the control. to get it to stop i'll have to go left and right or up and down again with the plow for it to stop. any ideas? could it be the control itself? the plow still works awesome no problems going up and down left or right it just keeps the motor on at times.


    SKYNYRD Senior Member
    Messages: 420

    best guess is the solenoid. when was it last changed? that's where i would start. only other guess is a short in the joystick providing you have the little square box one
  3. Ziob34

    Ziob34 Senior Member
    Messages: 182

    i have the little square box one with the on off switch on the left side.....maybe i can try replacing that. seems to usually only happen going up and down usually only up when i pick the plow up and let go it sticks on. weird cuz it works fine maybe its the relay solenoid to the pump? not the solenoidds on the pump itself as they seem to work fine.

    SKYNYRD Senior Member
    Messages: 420

    i'm not familiar with the mm1 system that's why i said my thoughts were guesses. you could try jumping the solenoid tht goes to the pump but i'm not sure if there's a way to test that other one =/ i'm sure if you're patient enough someone else on here will see your post and help ya out :) good luck!
  5. justme-

    justme- 2000 Club Member
    Messages: 2,138

    If you're going to just throw parts at it to fix it replace the solinoid first- it's a lot cheaper than the control box. They can fail and stick shut, but it's not likely that moving the control to another position wouldn't be likely to get it to break the connection if it is stuck.
    Never had that problem, but I don't think there is much else besides the control box to cause that....

    The fact it's am MM1 doesn't matter. The differences are is it an SEHP or an Insta-act, and is it a 3 plug or 3 plug.
  6. Ziob34

    Ziob34 Senior Member
    Messages: 182

    so probably best bet is its the control box in the truck thats causing the problems? i'm gonna replace its solenoid under the hood anyway its like a 20 dollar part just to be sure.
  7. Crash935

    Crash935 2000 Club Member
    Messages: 2,377

    Change the motor solenoid under the hood, its sticking. Dont mess with the controller.
  8. no lead

    no lead PlowSite.com Addict
    Messages: 1,308

    i concur with crash. might check batt connections. low voltage will make it stick.
  9. Ziob34

    Ziob34 Senior Member
    Messages: 182

    thanks guys changing it today will see if it works
  10. Acmemechanic

    Acmemechanic Senior Member
    Messages: 137