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Fisher MM1 acting funny

Discussion in 'Fisher Engineering Discussion' started by cbnh, Jan 15, 2014.

  1. cbnh

    cbnh Junior Member
    from NH
    Messages: 2

    New solenoid 2 years ago.

    Problems are the truck requires a trickle charge if seated for more than a day.

    Today, anytime I tried to place plow in "Float" to push down on the hydraulics so I could remove the plow, I was either (A) weak, or (B) the Float was locked out. Considering I did this two weeks ago, I rather go with choice B here.

    Sometimes but not always, when pushing the joystick right, the plow will go right. Then I push the joystick left, and the plow goes right, then I push the joystick up, and the plow goes right. After a power cycle it usually reverts to normal.

    Today for the first time it went stick up/plow up, stick right/plow up, stick left/plow up.

    My guess is a joystick control board issue. I thought I heard a relay in the control box at the plow head, but not sure if that is related. Any other guesses out there?

    Thanks much.
  2. justme-

    justme- 2000 Club Member
    Messages: 2,138

    Check the plug from the plow to the truck - the pins/sockets may need a cleaning or may not be seated correctly. IIRC, that is exactly what mine does when it's not all the way plugged in.
    I'll check the mechanics guide for the control pinout/testing later tonight.
  3. cbnh

    cbnh Junior Member
    from NH
    Messages: 2


    I've been having probs w/ that connection all the time... it's always loose.

    Do you think this is related to the parasitic power leak I'm seeing? Or do you think the joystick could be going, too? I did notice the joystick power light was dimmer at one point while trying to diagnose the issue.

    Other than dielectric grease, any tips for keeping good contact? I could use a vice grip, but I don't want to oversqueeze the connection... that might make things worse.

    - cbnh
  4. dieselss

    dieselss PlowSite Fanatic
    Messages: 11,392

    spread the pins out at the grill connectors
    then maybe try another good controller
  5. justme-

    justme- 2000 Club Member
    Messages: 2,138

    The old plugs the pins were stamped so they could be spread slightly with a tool... I took an old flat screwdriver and ground it into a sharper edge. The female sockets I have read also can loosen and can be tightened (as I have read but never done) by staking the connector next to the offending socket. That would be using something as a punch to displace some of the socket wall in the connector to make it tighter. The newer plugs have solid male pins so if you have a replacement end on your harness odds are it's solid. I recently found a company making "bullet" connector cleaning tools and they sell a set of 3 for snowplows, specifically listing Fisher plows... going to order and try them soon.

    I've never found a dimmer LED condition in my control (joystick). It's either on or off. There are several methods for cleaning connections... I like break clean or contact cleaner to remove the old grease and dirt, then a connector cleaner commercial ones are very expensive, like Deoxit... or homemade is super saturate white vinager with table salt and soak the connection or any rusted/oxidized steel/copper (never aluminum) in it for 20 min to several days depending on the progress you observe. Then neutralize with water that has been super saturated with baking soda. Works good on copper wires and most electrical connections on vehicles. I soak for 20 min to an hour depending on average.

    Here's Fisher's SEHP mechanics
    ... it will help you figure out the system.
    If you have the insta-act MM1 you want this one.

    Those plugs were always loose - the metal clip is supposed to help them stay connected. I always connect it (rubber cover stretches to just clip the metal ears when plugged in) but think it's marginal when the plug needs attention anyway.