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Changed Solenoid, Motor runs constantly when plugged in. Ultramount

Discussion in 'Western Plows Discussion' started by roket77, Dec 26, 2011.

  1. roket77

    roket77 Junior Member
    Messages: 18

    This is a Western Ultramount..Im assuming there were no problems with my plow because it had not been hooked up for a week. Last time i used plow,,everything worked correctly. I decided to put in a new solenoid because other one was 3+ years old. I bought the solenoid that is more narrow, not the Ford type solenoid. The parts store gave me two options but i went with the same style that had been in truck. We changed each wire one at a time so we knew we were putting each wire on its correct place. After installing new solenoid, we hooked up plow and after i had made its first movement with controller, the plow motor continued to run. The only way to turn it off was to unplug the harness that goes directly to the motor. This plow has three harness plugs, one for power to motor,and other two for lights and control. Even with other two(lights/control) harness plugs unattatched to truck,when I plug in harness plug from plow motor to truck side plug,,the plow motor runs,,this also happens when cab control is not attatched. We hooked up plow to my friends truck and everything worked fine. What could cause this condition. Sorry this was so long but i wanted to add as much detail as possible. Thanks for all and any help.
  2. cubicinches

    cubicinches PlowSite.com Addict
    Messages: 1,415

    The new relay is stuck. Put the old one back on.
  3. roket77

    roket77 Junior Member
    Messages: 18

    i guess ill buy a new one. Old nuts were so rusted, i had to break the small posts off so i could remove the smaller nuts. Are you pretty confident?? Thank you for your help.
  4. cubicinches

    cubicinches PlowSite.com Addict
    Messages: 1,415

    Pretty much. The fact that it runs with everthing unplugged other than the battery cable pretty much rules out everything else.

    You could do a quick test and remove the wires from the small terminals on the relay... on the outside chance that you've developed a short which is keeping the relay energized. Sounds unlikely, being that you only changed the relay as a preventative measure.
  5. Tony350

    Tony350 Senior Member
    Messages: 546

    I agree with cubic inches. But to check take a test light and check that both terminals don't have constant power. If they both have 12 volts all the time it is probably your new solenoid. The other thing to check would be is that the little wire on the solenoid doesn't have a constant 12 volts because if it does that would cause the solenoid to stay hot.
  6. cubicinches

    cubicinches PlowSite.com Addict
    Messages: 1,415

    Both large terminals on the relay are going to be hot... That's why the motor is running. The only thing the positive side of the battery cable to the plow is hooked to is that relay... so if the motor is running... it's hot. :) The question is why...??

    But you're correct about testing the small terminals, as that will keep the relay energized if they are staying hot for some reason.
  7. mishnick

    mishnick 2000 Club Member
    Messages: 2,353

    If you didn't put exactly the same type of relay back in I suspect you have a different type of relay alltogether. If you bought it from a napa or auto value or something like that they probably sold you a starter relay. They come in numerous configurations. The two big terminals are the same as a plow relay but the small ones could be different. On a plow relay the small ones are simply the two ends of the magnetic coil. A traditional old starter relay has one small lug connected to the coil + while the other end of the coil is internally grounded. The second small terminal was what they called the ignition resistor bypass. It's purpose was to send full 12 volts to the ignition system while cranking. This second terminal puts battery voltage out that pin when the relay is closed. Depending on how your wires are connected externally it could cause any number of problems. Other than this the only alternative is that you mixed things up during the changeover. Possibly, but not likely, the relay is bad from new. Just try disconnecting the wires from the two small terminals and see if it opens the curcuit. Even if it doesn't open the relay try tapping the relay with a small hammer with the small wires off. If it is sticky it may just release, but even if it does the relay is going to stick again if that is the problem.