plow locked up

Discussion in 'Truck & Equipment Repair' started by Jehnings, Feb 15, 2008.

  1. Jehnings

    Jehnings Junior Member
    from Ct
    Messages: 1

    I have a Fisher MM plow with the Insta-Act motor/pump. I use the fish-stick controller. The plow seemed to be fine until a few weeks ago. The first thing that happened it that the 12vdc relay to the Insta-Act motor/pump burnt out. I replaced that. The plow worked fine for a while. I have since removed and reinstalled the plow. The plow blade is not completely locked up. It is full angled to the right and won’t lift or angle left. When I press the controller buttons I can hear the motor kick on. It shakes and the light dim but the blade does not move at all. I can not manually move the blade to angle left. Almost like the hydraulics are bound. Any idea what the problem could be?
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,755

    The S3 valve isn't opening. Could be a problem with the actual valve itself, or the wiring/coil that activates it.

    Start with checking the coil for magnetism with a wrench or screwdriver while a helper holds the controller in the left or raise function. Does the coil have magnetism?

    You can download the repair manual off Fishers website to familiarize yourself with the hydro unit layout and wiring.