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ultramount low beam not working

Discussion in 'Western Plows Discussion' started by shadowj38, Feb 11, 2014.

  1. shadowj38

    shadowj38 Junior Member
    from pa
    Messages: 13

    I have a 3 plug isolation module ultramount with a low beam that won't work. The power transfers from my truck and turns my truck likes off but won't light my left plow light. Both high beams work just not my left low beam. I can see the elements in the bulb glow so i know its getting power. It just won't light. Where should I start?
     
  2. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    If you can see the filament in the lamp glowing it would indicate that there is not enough current flowing to fully light it up. If left high beam works we know the common ground is OK. First I would try switching the bulbs from one side to the other just to be sure. If problem moves to the other side you have a bum bulb. If the left low still doesn't work you need to start checking for a bad wire. Your lights have separate wires for each side and for each beam so if the left low beam wire is broken or corroded somewhere it would explain it. Check your grill plug, the one with 11 pins. Also check your isolation module plug port A, that's the output for all lights going to plow via grill plug. Look for bent / corroded pins. Left low beam power is on a solid black wire all the way from isolation module to bulb.
     
  3. shadowj38

    shadowj38 Junior Member
    from pa
    Messages: 13

    Thanks for the response. I never had an issue with this untill 2 weeks ago I was on my way home from work and it went out. I have still been using it because I've been too busy to look into it yet. And I did notice one night i had my highbeams on and when I clicked to low beams my right light was very dim. Then slowly lit to normal. I'm sure this is part of the issue but since its working now how do i trace that?
     
  4. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    Same process. Look at grill plug and ISO mode plug A. Look for green corroded pins. Clean up any corrosion u find and put some dielectric grease on them to keep them clean.
    I would shake the cable with light on low beam and see if u can make it fail. Where the shaking causes it to go dim should help u find the bad connection.
     
  5. shadowj38

    shadowj38 Junior Member
    from pa
    Messages: 13

    I checked the voltage at the plug for my light bulb. I have 12 volts on the low beam side and 12 volts on the high beam side. i also ran a continuity test from the plug at the module to the plug for the light on the ground wire, and the ground is good. I'm really leaning towards an issue with my module. It seems thats the only thing it could be unless I'm missing something else. Thanks again for your help!
     
  6. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    So u have 12 v but was it under load? If u checked when not connected then it's only half the test. U need to read that voltage while the light is connected. Voltage is just pressure. U won't see a voltage drop unless there is current flowing. It could very well l, and probably is the isolation module though from what u r saying. Would b nice if u could try one.
     
  7. shadowj38

    shadowj38 Junior Member
    from pa
    Messages: 13

    My dad's friend has the same set up I do. He said I could try his module to see if that's the issue.
     
  8. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    That would be the easiest thing. Three plugs and u have an answer.