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760 LT won't lower

Discussion in 'Blizzard Plows Discussion' started by Blizzard 760LT, Jan 20, 2015.

  1. Blizzard 760LT

    Blizzard 760LT Junior Member
    Messages: 15

    Plow was functioning fine, then raised, and won't lower from float controller or from power hitch switch.

    1) from controller: no drop, no noise (though I know usually is not anyway)

    2) from power hitch switch: can hear pump active when try to raise and lower, but won't move. (it is fully lifted, so won't go higher)

    Yes, lifted all the way, and now can't get cover off. I do know there IS ample fluid.
    I do know I will have to support plow and break loose a line to the lift cylinder to drop the plow.
    ANY HELP OR SUGGESTIONS?
    My thoughts are possibly the diode or the coil?

    Thank you in advance for advice. I do appreciate the time each of you take to help out! Thumbs Up
     
  2. Mr.Markus

    Mr.Markus PlowSite Fanatic
    Messages: 5,176

    Did you clean out and securely reconnect your main connectors?
     
  3. Blizzard 760LT

    Blizzard 760LT Junior Member
    Messages: 15

    Yes. Thank you. I can hear the pump engage and run, but no movement.
     
  4. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,979

    Crack the line loose and let it lower.
    First put a Jack under it and let the jack "lower it"
     
  5. Blizzard 760LT

    Blizzard 760LT Junior Member
    Messages: 15

    Thank you, but this is the part that I do know already as it states in the post. I am stuck and needing assistance to get an idea if it is the wiring on the plow side (namely the diode pack), or if it is more likely on of the coils. I do appreciate your help.
     
  6. Mr.Markus

    Mr.Markus PlowSite Fanatic
    Messages: 5,176

    Is it outside in the cold and just frozen?.. Hit it hith a heat gun or space heater for a bit...
     
  7. Blizzard 760LT

    Blizzard 760LT Junior Member
    Messages: 15

    Thank you Mr. Markus. It was initially in my garage. I put it on the truck and was working fine. Approx 1 1/2 hr into route is when it quit lowering. I agree, it may have frozen, though it hasn't had this issue before in even colder temps. I will try that before I take it off the truck tonight.
     
  8. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,979

    You can't get to the motor or coils as it sits, so what's the big deal with cracking the hydraulic line lose and lowering it that way, and then getting access to the hydraulic system, and coils
     
  9. Mr.Markus

    Mr.Markus PlowSite Fanatic
    Messages: 5,176

    I was stumped by a frozen blizzard once, it doesn't take much, even one frozen fitting bungs it all up.
    I put mine in a heated shop to work on it and by the time I put my coveralls on it was working again. Sometimes adding some ethylene glycol to the fluid works too.
     
  10. Blizzard 760LT

    Blizzard 760LT Junior Member
    Messages: 15

    diesels. Sorry, I think you were misunderstanding my needs is all. I know I cannot get to anything with it lifted and the cover on. I am not bound up there. I know what it will take to lower it. You are correct, that is NOT a big deal. I am trying to trouble shoot the actual issues that may be causing it to NOT LOWER how it is supposed to while I plow, as I cannot get out and crack a valve each time I want to drop the plow to push snow.
     
  11. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,979

    No, I get your point. Make it as hard as possible right now.
    So you can't access the hydraulics, can't pinpoint test the coils, or even see if a wire is broken under the cover. But yet you still wanna know how test it without access to the hydros.
     
  12. cl733

    cl733 Senior Member
    from Canada
    Messages: 252

    Is your side to side working as well, if so when you do get it down check to be sure your connection for grounds have all ground wires fully engaged, if none of the above seem to be working see if your bolt holding grounds to frame are tight with all wires crimped in, open up your blade drop speed abit, bee sure it never tightened itself up,
     
  13. Blizzard 760LT

    Blizzard 760LT Junior Member
    Messages: 15

    Yes, side to side is working. I also can hear the pump working when I use the power hitch to attempt to drop it. Thank you.
     
  14. cl733

    cl733 Senior Member
    from Canada
    Messages: 252

    then a desperate measure would be to look under your motor cover and find the 2 solenoids that need to be activated to drop the power hitch, you can run a couple of short wires from your positive on your motor, with the help of a couple of alligator clips, to the two solenoids needed to drop the power hitch , when you do a command from the controller it will start the pump and should drop your hitch ,I would still try opening up your blade drop speed a little to be sure its not run itself in too far. I found on a blade we had that we had to take the cartridges out and put the coils on the removed cartridge and actually check for movement, we ended up changing out a coil
     
  15. bliz&hinikerDLR

    bliz&hinikerDLR Senior Member
    Messages: 471

    Likely S5 coil ... diode pack less likely.

    Support plow and lower it enough to remove pump cover. Confirm flow control valve not turned all the way in. Put plow in float and check for magnetism at S5:
    No magnetism at S5:
    check for power to S5 coil: No power = electrical problem Power = bad coil
    Magnetism at S5:
    confirm coil provides enough magnetism by putting S8 coil on S5 valve then activating a lower function at PH switch: Plow drops = bad S5 coil Plow does not drop = hydraulic problem
    Hydraulic Problem:
    Support plow completely with jack stands. Remove, inspect, clean and test S5 valve. Replace if necessary.

    I left out the common sense steps since it seems you have got some got that covered. Let me know if your still stuck.
     
  16. Blizzard 760LT

    Blizzard 760LT Junior Member
    Messages: 15

    Thank you. That's what I was looking for. An starting point and what to expect and look for. This way I can tackle a few years at once and not have to run to the computer after each one.
     
  17. Blizzard 760LT

    Blizzard 760LT Junior Member
    Messages: 15

    bliz&hinikerDLR, would the coil have the ability to work intermittently?
    Here is what I have done so far, and was at least able to finish the last couple of driveways. I am going to dig into it this weekend.
    Broke hydro line to lower plow. Tightened it back up and it lifted and lowered by the PH. It seems as though when it is fully lifted is when it will not lower. Then, it would lower from the PH, but not the float position on controller (worked intermittently)
    Fluid is clean and full, all wires are in great shape (no cracks or breaks), all wires are connected securely, Coils were not too tight.

    Thank you again for your help.


    Fliud: Fine