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Down pressure problems

Discussion in 'Sno-Way Discussion' started by vtnyspace, Oct 28, 2009.

  1. vtnyspace

    vtnyspace Junior Member
    Messages: 13

    Just got my used 7 1/2 foot Predator HTD hooked up to my truck.
    Everything works great but the DP.
    I also just installed new wireless module and remote.
    With DP on and push down button - blade just drops down with gravity.
    If DP is off, run blade up and down then turn on DP- seems to twitch and release pressure on cylinder- motor runs for split second- one time only. Seems it does this twitch thing
    every 20 to 30 seconds if leave DP on- not sure if it does this all the time.
    Have power at brown wire to DP switch. Good continuity on yel. wire from switch to
    module connector.
    If I disconnect DP switch and use test lead across brn and yel harness wires it
    goes into DP position and motor runs until I disconnect.- without touching remote
    control.
    Would any of you experts like to comment? Basher?
    Thanks in advance.
     
  2. ondagawood

    ondagawood Senior Member
    Messages: 128

    I've heard some remotes were defective (recall maybe), are your batteries fresh too ?

    Contact a dealer or someone here, about possible defect remote.

    Good luck,
    Scott
     
  3. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

    It could be a bad pressure switch, was it working properly with your old control system?

    Check to see if the pins in the control plug are properly set in position. Sometimes the factory doesn't get them locked and they "float" in the plug making intermittent contact. if it was working properly until you changed the control I would check that first.
     
  4. vtnyspace

    vtnyspace Junior Member
    Messages: 13

    The pins on plow side of connector look perfect. the female terminals in new module connectors look fine too.
    I just bought this plow used about a month ago- it looks like it was hardly used- said his son used it for part of a season.
    I believe it has been sitting unused for several years.
    The remote that came with it was left outside and corodded. Local dealer let me try one of their corded remotes- it powered up but did nothing- module was bad.
    That is why I replaced w/cordless system- Just bought it from sno-way dealer.
    So I don't know when DP worked last on this plow.
    Thanks.
     
  5. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

    I think i would drain and flush the system. Drain all the rams hoses and tank, reassmble fill with Meyer hydra-flush and cycle it repeatedly though all functions. Could just be sticky valves.
     
  6. vtnyspace

    vtnyspace Junior Member
    Messages: 13

    Thanks Basher.
    I found procedure to drain all oil from reservoir and cylinders in manual.
    Then I fill/bleed with Meyer Hydra Flush and run plow all angles/up/down etc. right?
    Maybe then it will loosen up possible stuck switch.
    The flushing fluid is just that - a flushing fluid right? will need to drain and refill with new proper oil right?.
    Is Dexron atf an approved fluid or should I stick to approved plow oil? The latest Dexron atf is supposed to be an awsome synthetic trans fluid.
    I asked for snow-way fluid at my dealer- didn't have any. He thought that techs there use atf.
    Will try that this weekend if I find the flushing fluid.
    Would removing DP switch and/or Dp relief valve help?
     
  7. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

    Not until you flush it well.
     
  8. BayStateGlenn

    BayStateGlenn Member
    Messages: 42

    Are you sure this plow even HAS down pressure???
    I believe it was an option on those models but I'm not positive.

    Edit to add:
    If it does have valving for down pressure there should be 6 valves, the "E" valve is the one that should be opening during that function.
    (at least that's the DP valve on the newer units)
    You can pull the valve and slide the coil back over it, touch a 9V batterie to the terminals and see if the valve opens.
    If not then bad coil or bad valve. Check it with another coil to determine which.
     
    Last edited: Oct 30, 2009
  9. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

    Remember while you are testing things that this unit is low side switched. That brown wire is a switched ground.

    Yes the "E" working in conjuction with the "B" and the pressure switch operate the DP.

    I'm more inclined to believe it is a failed or clogged pressure switch, it sounds like the DP is trying to spool up up but gets incorrect information from the switch.
     
  10. vtnyspace

    vtnyspace Junior Member
    Messages: 13

    Basher- I am having trouble getting the Meyer Hydra flush. Few dealers in my area and nobody stocks it. Northern tool has it on their website by the case only. I called a local store and they don't stock it.
    Could I use old type non synthetic atf to flush it out? ATF is highly detergent to clean parts. Then drain and refill with proper fluid.

    When transmitter is turned on- have battery power at both small posts of solenoid-
    brown wires and red/white stripe wires.
    I checked Monarch repair manual but they don't explain exactly how the DP wiring system works.
    I assume the module controls the polarity of wires to the small posts to determine
    whether the module controls operation or dp switch controls operation.
    Looks like someone replaced motor solenoid switch- must be wired right - shouldn't matter which wire goes to which on small posts. Besides all other functions but DP work fine.
    Thanks again.
     
  11. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

  12. vtnyspace

    vtnyspace Junior Member
    Messages: 13

    Using atf then flushing by removing reservoir, cylinder hoses and pushing all atf out should be okay right? or refill again with proper oil, work it and do proper oil again?

    I already saw that wiring diagram, but it doesn't show direction for flow of electricity in each mode.
    That makes it kind of hard to understand exactly how it works.
    Has theory of operation in same manual, still vague.
    Thanks for all info Basher.

    vtnyspace.
     
  13. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

    no problem:waving:
     
  14. vtnyspace

    vtnyspace Junior Member
    Messages: 13

    Red/wht. stripe wires have power w/transmitter is turned on- also power at other small post.(brown wires) even when wires are disconnected from dp switch.
    Power at both posts has to be coming from module.
    Unless something is wired wrong/bad motor solenoid?
    All wiring is/looks good and original.
    No power at yellow to dp sw.
    ?
     
  15. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

    Right Low side switched. Power everywhere, when the function is activated the test light goes out because you have activated the grounds.
     
  16. vtnyspace

    vtnyspace Junior Member
    Messages: 13

    Basher, thanks for previous info.
    I removed reservoir, hoses and pushed all old fluid out. refilled with regular atf..
    Been over a week, running it all functions once in a while.
    Still works about he same with dp inop. but now with dp turned on and lift all way up and hit down button, it drops normally but the motor pulses on and off rapidly as it drops to floor and few pulses after all way down.
    Also noticed-(may have been there before) that with dp on and blade on floor, if I tap either
    angle button it will go into dp mode and lifts frt of truck slightly. If hold button down it angles normally without going into dp mode.- have to quicly tap button to make it do this.
    Threads on motor solenoid posts were kind of screwed up so I replaced with brand new Sno-way solenoid. still works exactly the same.

    Kind of weird- can you please comment? Thanks.
    Plow will work fine as is but since it has dp, sure would be nice if it would work.
     
  17. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

    Bad pressure switch or valve would be my quess.
     
  18. vtnyspace

    vtnyspace Junior Member
    Messages: 13

    Basher,
    Pressure switch or valve- I know which one the pressure switch is but is the valve you are referring to must be the down pressure relief valve?
    Over a hundo each I suppose.
    Sure wish I knew someone else who had one of these plows so I could swap out pressure switch and see what happens.
    Is there any adjustments on the press. relief valve?
    Thanks man.
     
  19. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,992

  20. vtnyspace

    vtnyspace Junior Member
    Messages: 13

    Basher- thanks for all your help.
    I finally broke down and replaced DP switch.- Now everything works as it should.
    One day I had the old switch out and hooked up ohm meter to leads.
    All I had to do to make it switch from closed to open was to put my mouth on the
    end and blow into it. Very weak switch.
    Flush atf out and refill with plow oil and I have an awsome plow.
    :drinkup: