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no power to controller/iso

Discussion in 'Western Plows Discussion' started by OBRYANMAINT, Dec 15, 2007.


    OBRYANMAINT PlowSite.com Veteran
    from ohio
    Messages: 534

    swapped plow from 05 to 07 chevy//ultra mount/iso box green sticker

    new solenoid

    swap seemed pretty easy,but getting no power to controller

    power at red wire fuse box tap
    2 fuses have power near iso box in and out
    black orange wire that ground system good
    hot to batt side of solenoid good
    i even grounded solenoid and that changed nothing
    checked power from fuse tap into iso box it is good

    plugged plow in and changed nothing

    i am thinking that i have an iso box that is bad?

    any ideas
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    If all your connections and fuses are good, then it's either a broken wire in the controller cord or the controller died on you..

    Does the controller even light up at all?

    The controller's die a lot more often than the Iso modules...

    You can disassemble the controller handle and check for power on the white and black wires right at the wire connections in the hand held...

    If you do in fact have power there, but still no power light, then the controller is dead..

    OBRYANMAINT PlowSite.com Veteran
    from ohio
    Messages: 534

    no light at all on controller...no power to controller

    not controller...swapped it to another truck and controller is ok

    went and bought an iso module....not that either

    i saw on some other posts that a ground is the answer

    i have looked it over pretty good i must be missing something

    wire loom is in great shape but could have a short......somewhere
    Last edited: Dec 15, 2007
  4. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Did you check the blk/org wire at the controller plug for ground?

    You should have a blk/org wire on one of the small terminals on the motor relay but you should also have a blk/org to the ground post on the battey...

    You can also run and additional ground wire from the battery to the motor relay post with the blk/org wire.
  5. FBC Turf

    FBC Turf Junior Member
    Messages: 6

    Last edited: Dec 16, 2007
  6. FBC Turf

    FBC Turf Junior Member
    Messages: 6

    I'm having the same problem. I cut the blk\org wire from wireharness to motor relay capped and then extended the blk\org from motor relay to ground (battery terminal). That is what the manual said.......is this wrong?

    Not to hijack the thread but I think we might be having the same problem. When the truck is running should both power terminals on the motor relay be energized? The battery side is HOT but the wire harness side is NOT. I believe that they should both be hot or else the wire harness is getting no power and nothing else down stream from relay would function. Now to the real Question.....can you ure a starter solenoid from say a 90's Ford to replace the motor relay? And if so are there any special requirements for the solenoid?
  7. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Are you doing a retrofit to the Cab Command from an old style joystick (Unimount relay system, or relay style Ultramount?) If you cut the blk/org from the harness to the small stud on the motor relay, and then ran a new wire from the motor relay to the neg side of the battery, you must also cut the blk/org wire in the cab near the control connector plug and run the connector side of the cut wire to the neg side of the battery also..

    Only the battery side of the motor relay should be hot until you press a function on the control that would require the motor to run (raise and angle) That's the purpose of the relay, to control the plow motor. The small brown/Red wire on one of the small terminals is what activates the relay. It should only be hot when any control function is pressed except lower/float.
    Theoretically yes, but there are several different styles that are wired differently internally.. most are marked "S" and "I" on the small terminals.. The S is the activation terminal but the "I" IS NOT A GROUND and if you connect your blk/org wire to it, you'll have a direct short when the relay is energized...
  8. FBC Turf

    FBC Turf Junior Member
    Messages: 6

    It is a brand new ultra mount on a 20008 Chevy 2500HD. I did the blk\org wire at the motor relay and the controller. The controller retrofit is not grounded at the battery but at the engine ground. Will this make a difference?

    With this new info about the relay only being hot on the battery side I'm thinking that the motor relay is not the problem. Does the plow have to be connected to the truck for the controller to light up?