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no low beams on my mm1

Discussion in 'Fisher Engineering Discussion' started by dankdizzle1017, Jan 9, 2011.

  1. dankdizzle1017

    dankdizzle1017 Junior Member
    Messages: 18

    I recently installed a plow on my gmc 1500. I have high beams but no low. I switched them around so the plow least has lights. Any ideas how to fix.
     
  2. snowman123

    snowman123 Senior Member
    Messages: 205

    Could you put a picture up of what you switched to get an idea.
     
  3. mikespenny

    mikespenny Junior Member
    Messages: 22

    If you have the old relay style setup there could be a few problems, electrical problem in the plug(was just fighting this with my angle problems), bad connections at the relays, or bad relays themselves.
     
  4. stg454

    stg454 Senior Member
    Messages: 113

    I am having the same problem. I believe that it is a bad relay. Just need to get the time to stop and get a new one. Let us know what you find
     
  5. dankdizzle1017

    dankdizzle1017 Junior Member
    Messages: 18

    I installed a brand new relay. I had high beams so I switched the high with the low beams, from the factory harness. Just to have lights. The light harness is the only wires I used from the other truck I took it out of
     
  6. mikespenny

    mikespenny Junior Member
    Messages: 22

  7. dankdizzle1017

    dankdizzle1017 Junior Member
    Messages: 18

    It's all hooked up the way its supposes to be, at least to my knowledge. The plow is a 99-00model.
     
  8. snowman123

    snowman123 Senior Member
    Messages: 205

    When you say you have no low beams does the light's go on at all.
     
  9. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    What year/body style is your GMC and what year/body style was the truck you removed the headlamp harness from? That's likey your issue.
     
  10. dankdizzle1017

    dankdizzle1017 Junior Member
    Messages: 18

    1500 extended cab 6 foot bed.i bought a new harness for the lights because knew the truck I took it out of wouldn't match
     
  11. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    What p/n harness did you buy and what year is your truck? We need to be sure you have the correct harness before going further.
     
  12. jaybird

    jaybird Member
    Messages: 40

    in 99 fisher went to the 6 relay harness for the for the chevy's and gmc for hb3 hb4 headlight system part # is 26070. that coud be your problem. just shooting from the hip from what your saying.
     
  13. dankdizzle1017

    dankdizzle1017 Junior Member
    Messages: 18

    Thanks guys just had to flip some wires around. Good thing I didn't take it to a dealer for a simple fix
     
  14. stg454

    stg454 Senior Member
    Messages: 113

    Well I installed the plow again tonight getting ready for the big storm. I installed new relays to try to solve my no low beam problem when the plow is connected. It is the same as before only have high beams with the plow connected. I do have an aftermarket headlight harness on the truck that uses relays to feed more power to the headlights. I have it wired so I disconnect the truck light ground when the plow is on so I only have the plow lights working with the plow. This is the harness that I used for the truck lights http://www.lmctruck.com/icatalog/de/full.aspx?Page=45. My truck is a 2001 Dodge Ram 2500 with an 8' MM1 with two wire set-up with the relay headlight wiring. Any ideas what the problem may be?
     
  15. stg454

    stg454 Senior Member
    Messages: 113

    Any ideas on my low beam headlight issue?
     
  16. snowman123

    snowman123 Senior Member
    Messages: 205

    stg454 did you buy the plow setup used if so what truck did it come off of and what truck is it going on now.
     
  17. stg454

    stg454 Senior Member
    Messages: 113

    I did buy the plow used. The ligt harness was given to me by a friend that runs a Fisher dealer. I believe that it came off a Ford. It was installed on an '01 Dodge Ram 2500.
     
  18. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    There's your problem. Your Dodge is positive common on the lows and a Ford is not. Need to re-pin the harness. Check the wiring schematics for both the Ford and Dodge harness on how to convert it.
     
  19. snowman123

    snowman123 Senior Member
    Messages: 205

    I had the same exact problem this pdf file will help you. Go to page 6 and page 15 this will tell you what wires you have to change around.
     

    Attached Files:

    Last edited: Jan 17, 2011
  20. stg454

    stg454 Senior Member
    Messages: 113

    how do I change the pins in the plugs?