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MM1 no left to right PLEASE help

Discussion in 'Truck & Equipment Repair' started by lbubba05, Nov 1, 2009.

  1. lbubba05

    lbubba05 Junior Member
    from Boston
    Messages: 2

    I recently became the owner of a 97 Chevy 1500 ext cab. This truck came with a Fisher MM1 7.6 plow. The plow sat unused for about 5 years. I hooked up the plow and it initially moved in ALL directions and than while moving it to the right angle position made a straining noise and will not move left anymore. Now it moves up,down and is stuck in the right angle position. Also when toggling right the plow reads the comand as a up comand instead. I am new to Fisher plows. Any Ideas? I need to get this reliable running ASAP. Thanks.
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Short in the wiring harness, corroded grill connector, or bad controller. Those are the only possibilities that can make it raise instead of angling to the right.
  3. lbubba05

    lbubba05 Junior Member
    from Boston
    Messages: 2

    Thanks. I will try chasing down the problem with each suggestion you made and post my results asap. Thanks again!
  4. plowguy43

    plowguy43 PlowSite Fanatic
    Messages: 5,281

    Check the Ground and Postive Cables to make sure they are correct on the plow AND the truck. I bought a Used MM1 that did this as well. Basically the electric motor was running in reverse because the previous owner hooked up the cables backwards on the silenoid (truck side). I couldn't get it to angle left unless I kept tapping the left button over and over again. I realized the problem, swapped with cables to the correct position and it works perfect now.
  5. gtstang8706

    gtstang8706 Member
    from MA
    Messages: 36

    Im having the same exact problem on my mm1 plow. its driving me nuts and if i cant figure it out soon Im plannning on bringing it to my local fisher repair guy:dizzy:
  6. no lead

    no lead PlowSite.com Addict
    Messages: 1,308

    a few questions and you should be on your way:
    what controller do you have?
    have someone run the controller and move the 9 pin connector back and forth.
    you said if you push right it goes up?
    what happens if you push left repeatedly?
    put the plow in the float position and try it left and right.

    can you verify that the coils magnetize during requested functions.
    answer these questions and a diagnosis should be made.
  7. DeAdZoNe

    DeAdZoNe Member
    Messages: 31

    If it has sat, it could be junk that got dislodged in the fluid when you first moved it and is now clogging up a valve.
    Also download the manual off the website and do the solenoid test. If one is not getting power from either a bad wire, ground, etc it could be similating your problems of up when pressing right. The exact same thing happened to my MM1 last year about 22 hours into a storm it would somtimes work. I got frustrated and mashed the plow into a snow bank while holding left and got the plow to "break free" I blew the rubbers on the poppet relieve valve but i got through the storm. After pulling it all apart I found metal shavings inside the valves (years of steel moving inside an alum. housing) Cleaned it up and that was the whole problem.