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hoping someone can help a newbie

Discussion in 'Commercial Snow Removal' started by gwnorth23, Aug 16, 2008.

  1. gwnorth23

    gwnorth23 Junior Member
    from Maine
    Messages: 27

    Just bought a used MM2, 7.5 rd, had the plates and electronics installed and all was well until I went to drop the blade. Will NOT lower, side to side and up is great, all lights look great and everything else works but no down. Any of you experienced guys willing to help out a newbie. Now I am in a pickle because I can't get it off my truck without draining the fluid out? Any thoughts would be greatly appreciated......Thanks, Mark

    :dizzy::realmad::realmad::realmad:
     
  2. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

    Check the 2 way valve. Make sure it's getting 12 volts and the coil is magnetic. If it has magnetism pull the valve (carefully it's under pressure right now) make sure the solenoid is operating correctly. Here's a link to the fisher guide.
    http://www.fishersnowplows.com/pdf/6395_000392.pdf
     
  3. gwnorth23

    gwnorth23 Junior Member
    from Maine
    Messages: 27

    Thanks, I am not sure how to perform what you stated above. I loosened the hydraulic line leading to the raise/lower ram and was able to force the ram down some. This allowed me to get the plow off the truck. Should there be any sound when trying to lower? There is no click/nothing when selecting lower/float on the joystck control...Mark:dizzy:
     
  4. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

    Let me back up, do you have under hood hyd. or ele/hyd?
     
  5. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    If you have an external hydro line on the lift ram then you have the Insta-Act pump unit. The manual Basher provided is for the old SEHP unit (50/50 chance of posting the correct one the first time :)). Here's the manual for your power unit: Insta-Act manual.

    Start with pg 45 for the coil/valve diagnostics (which is what Basher was referencing to). It'll lead you through all troubleshooting you should need.

    For additional references you can also use the search words "magnetism" or "grill connector" in the Fisher forum here on PS. Tons of reading on diagnosing coils/valves trouble.
     
  6. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

    yeah jumped the gun there should have asked a couple questions first:nod: He said older i thought SEHP never considered underhood.
     
  7. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    You wont hear the under hood solenoid (for the pump) click when the lower/float button is pressed, as the motor doesn't run for the lower/float function...but if you have an assistant listen really close you should be able to hear the S2 valve/coil assembly click ever so slightly if it's getting power and the valve is shifting. You can check it with a wrench or screwdriver for magnetizem as well...check out the manual, its all there. :)
     
  8. elite1msmith

    elite1msmith 2000 Club Member
    from chicago
    Messages: 2,762

    when you lossened the the hydro line, the plow should have just fallen down, even by cracking open the line...you said you had to force it...like push down on the lift arm?

    sould like the packing nut seal is jamming the ram , if you forced it down?
     
  9. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    If the packings were holding it up, opening the line to relieve the fluid pressure wouldn't allow it to lower either. :)
     
  10. elite1msmith

    elite1msmith 2000 Club Member
    from chicago
    Messages: 2,762

    yes imn aware that lossening the lines alone wouldnt do it.... but when he said he forced it down,...maybe jumppin gon it , after lossening the line?

    or did you just lossen the line and it went down on its own?
     
  11. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    I would have to believe he meant that the weight of the plow pushed the ram down. Because if it wouldn't then no body weight other than big Bubba himself is gonna do it either.
     
  12. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

    I would think that if the packing nut was tight enough to stop the blade from dropping he wouldn't be saying it goes up fine.I'd think it would go up slowly, and probably screech while doing it.
     
  13. elite1msmith

    elite1msmith 2000 Club Member
    from chicago
    Messages: 2,762

    true, but seen it ,and done it - before thats all i ment

    and to "force somthing down" sounds misleading or as i take it
     
  14. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

    Yeah I've used a 5 foot bar to help the blade down a time or three:nod:
     
  15. gwnorth23

    gwnorth23 Junior Member
    from Maine
    Messages: 27

    "Disconnect the red (+) battery cable from the motor and isolate it" Can anyone tell me the steps here? Are they just saying to cut power to the plow pump motor? If so, when I cut power how will the magnet test work on the coils, sorry for my ignorance here I just would like to try and solve this myself vs $60/hr diagnosis:) I am just wondering how steps 3 & 4 on page 45 of the InstaAct manual will work if I cut the power.......Mark
     
    Last edited: Aug 17, 2008
  16. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

    Don't cut it, disconnect it at the terminal stud on the motor or from the battery. This will stop the motor from running while you're checking the coils. The coils will still get power from the control, only the motor won't work. It helps if you have a skinny wrench to hold the rear nut on the stud. You don't want to spin the terminal and break it loose from the brushes.

    $60 an hour is

    1; just plain cheap for technical service work, walk in to your local auto dealer service center and look at their prices:eek:

    2; a lot cheaper then buying a nonreturnable part you don't need.

    Call the guy who installed it the labor might be negotiable if the dealer just installed the plow. I cann't speak for the world but whether or not it was our fault we'd probably just bill the part in that situation. Helps build customer loyalty.

    Also could be a install error, loose or pinched/cut/broken wire. Even I :rolleyes:(and any other honest tech) make mistakes. Could be good for your dealer relations, we're always extra attentive to a customer whom has had a problem of our making. If he's any good he;ll remember you and make sure you get GOOD service the next time you need something as a thanks for your giving him a second chance.

    But there's a lot to be said for knowing how to fix the stupid stuff yourself.
     
  17. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Mark, in your specific case it's not necessary to disconnect the power cable/cables to the pump as your only having the issue with the lower/float function, which the pump doesn't run in anyway. Never hurts from a safety standpoint, but not totally necessary.
     
  18. gwnorth23

    gwnorth23 Junior Member
    from Maine
    Messages: 27

    First off I just wanted to say thanks to everyone that responded and that after several attempts I was able to get the plow to go down! While it wasn't one of the things recommended it taught me alot about the plow and gave me some great info for the future. It was the connection from the joystick to the wiring in the dash. I wiggled it while holding down on the stick and it started working. Now I have to take the bottom half of the dash off to see where the loose connection is as I can't access it by looking up under the steering wheel. Hopefully won't be too bad to take that panel off (2003 GMC) and take a look at where the controller connects to the harness. Thanks again! Mark
     
  19. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Good to hear you have it narrowed down Mark. Surprising how much knowledge you can gain with a good manual and a little time isn't it?

    Sounds like either the connector pin for the S2 isn't making good connection where the controller connects into the harness...or the S2 wire is damaged (possibly from installation).

    Removing the lower panel is easy. First pop the plastic trim plate off surrounding the instrument cluster. No screws or fasteners on that one, just grasp it and gently pull. Be sure to tilt the steering wheel all the way down and also place the shifter in manual 1st (if its an auto) to allow the trim plate to come out. Then simply remove the few screws holding the lower panel on and remove it.
     
  20. gwnorth23

    gwnorth23 Junior Member
    from Maine
    Messages: 27

    Thanks B&B and what color is the S2 wire, light green? And does it trace all the way back to the joystick? Thanks, Mark
     
    Last edited: Aug 19, 2008