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irratic mm2 movement

Discussion in 'Fisher Engineering Discussion' started by aggrivated, Mar 28, 2008.

  1. aggrivated

    aggrivated Junior Member
    Messages: 2

    i bought a used mm2 sometimes it works fine and sometimes it is very irratic. it will
    always angle right with no problem, occasionally pause and seize up when trying to lift, and the most annoying problem is upon angling left sometimes it will start moving left and the suddenly bounce and go to the right, once all the way to the right it will not go back without a few minutes of tapping the button to move it left rappidly. then it will clear up and act fine for a bit. i checked all the connections wiggled them cleaned them checked for corrosion cleaned the three valve plugs numerous times and took the controller apart to see if anything was burnt. i know the conrtoller gets warm from the light and i am lead to believe that the controller is bad but nervous about buying one. am i on the right path?
  2. Bruce'sEx

    Bruce'sEx Senior Member
    Messages: 873

    Three plug setup?

    There could be a problem on the wires coming off the valve controls. One of the MM1s this year you would tap the control to drop. and it would not do anything for like 30 seconds. then it would drop. turned out it was a problem with the harness of the valve body, the electric soleniods. might be the same with you. thats all I can think of
  3. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    The S3 valve not opening or staying open is the reason it wont raise or angle left when the function is pressed. But it's probably not a fault in the valve itself (like contamination). Since you stated that it will at time start to angle left and then suddenly go to the right instead leads me to the conclusion that the electrical signal is initially there to shift the valve but then it's losing it for one reason or another. Need to check for 12V on the light blue wire at the valve coil when it's acting up to see if the signal is getting from the controller to the valve coil. If you find the 12V isn't there then you can back track through the harness with a test light to see if the controller is even sending the signal out at all. The wire is light blue all the way to the controller connector under the dash. If you find the signal isn't coming out of the controller then its a good bet the controller is defective. Check right at the bottom of the controller handle where the wire exit, they like to break the wires there, causing intermittent or unresponsiveness of specific functions.

    Also make sure the black/orange ground wire on the valve coil(s) also has a good connection at the coil and has good ground. Many times these intermittent problems are simply a loose black/orange ground wire on the plow side harness.
  4. Yaz

    Yaz PlowSite.com Addict
    from NH
    Messages: 1,061

    B&B is right on with this.. I would get the electrical and hydraulic schematic from the Fisher's web page and keep it in the truck. It a great guide for trouble shooting. You see to make various movement single and multiple solenoids open valves and close. So if your trouble is with two movements, look for the valve that common to the two...Get it?:rolleyes:
  5. BigLou80

    BigLou80 Senior Member
    Messages: 558

    My plow went nuts when the selenoid was sticking causing the pump to run constantly or not at all. It would angle eraticaly or fail to move other times. stoped by the local dealer during the snow storm the handed me a new one and said we don't have time to install it. 5 minutes later problem solved

  6. BigDave12768

    BigDave12768 PlowSite.com Addict
    Messages: 1,446

    I had same problem with my old MM1. Others gave you good things to check. But I found mine was a bad ground. I never really got into it I just made a new ground wire of the pump. So you can try this for an easy type fix/check. Run a wire from ground on pump to battery ground. If you are trouble free then just make a ground wire to plow frame.it fixed all my problems
  7. aggrivated

    aggrivated Junior Member
    Messages: 2

    ill def try that it sounds simple enough and cheap therefore making it an achievable first step haha hope to have this cleared up by next winter.... GO PATS... its not over yet haha