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MM1 3 plug lights issue

Discussion in 'Fisher Engineering Discussion' started by TMacie, Nov 29, 2014.

  1. TMacie

    TMacie Junior Member
    Messages: 22

    Hi All,
    I have a 99 ram 2500 with a MM1 and 4 port module. I have the one dim light issue. I've swapped the config plug, one way I get no driver side light, the other I get a dim light. This is both high and low beam.

    I've also made a harness to completely bypass the truck lighting. The harness plugs into the fisher wiring input. Unfortunately, the lights don't light at all when using this harness. The relays click over and there is power going to the fisher harness, but the lights don't work at all. I'm wondering if the Iso module needs to "see" the truck lights to switch over.

    Any help would be appreciated.

    Thanks,
    Travis
     
  2. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,983

    This a new install?
     
  3. TMacie

    TMacie Junior Member
    Messages: 22

    Its been on the truck for a couple years, from another truck where it worked fine. The truck was the same year ram.

    Thanks,
    Travis
     
  4. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,983

    And it just started?
     
  5. TMacie

    TMacie Junior Member
    Messages: 22

    No, its always been this way on this truck. Basically, I got a new plow that is higher than the last one, now I have to have the lights working properly.


    Travis
     
  6. TMacie

    TMacie Junior Member
    Messages: 22

    A little update. I spent some time outside with the wiring. My harness is now working and the isolation module is passing current to the lights. There is voltage at the proper places at the input harness to the Isolation module on both sides, BUT only the passenger light works. If i swap the configuration plug the passenger light still works and the driver light comes on very dim, both low and high beam.

    If I swap the yellow and blue pins at the isolation module, the lights both work, but are very very dim. Both low and high beam.

    Thanks,
    Travis
     
  7. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,983

    So the plow was on another trk and all worked.
    You put it on this trk and it never worked right?
    What year was the old trk? Might have the wrong harness
     
  8. TMacie

    TMacie Junior Member
    Messages: 22

    Yep, same year truck. 99.

    Take a look at the update I posted. Right now its running on a harness I made with relays. I am 100% sure my harness is wired properly. I've tested it and power is where it should be. Its not even wired to the truck wiring right now.


    Travis
     
  9. Arc Burn

    Arc Burn PlowSite.com Addict
    Messages: 1,139

    Check your truck side headlight bulbs,if i remember correctly in 99' Dodge actually sent out a run of vehicles with 2 different bulbs from driver side to pass side,connectors will be similar but the power at the pins will be different.
     
  10. TMacie

    TMacie Junior Member
    Messages: 22

    Arc Burn,
    The bulbs are the same. 9004 bulbs.

    Travis
     
  11. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,983

    Here's a few wiring diagrams. There western but they should be the same

    tmp_11008-Screenshot_2014-11-13-03-39-431772416500.jpg

    tmp_11008-Screenshot_2014-11-13-03-46-42-1472558706.jpg

    Screenshot_2014-10-15-18-30-17.jpg
     
  12. TMacie

    TMacie Junior Member
    Messages: 22

    Any chance you can send me the link to the last diagram? I cant blow it up enough to reed what the wires do. I'll verify that the wiring is correct in the harness.

    Thanks for the help.

    Travis
     
  13. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,983

  14. TMacie

    TMacie Junior Member
    Messages: 22

    Heh, i just found it too. thanks.
     
  15. TMacie

    TMacie Junior Member
    Messages: 22

    Ok, so all the wiring matches what is in that diagram.....any more thoughts?
     
  16. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,983

    So just outta the blue they turned dim.?
    I'm saying Ck the gnd. They go bad outta no where. Try and run a "new" gnd to where the headlights are gnded on the trk
     
    Last edited: Nov 29, 2014
  17. TMacie

    TMacie Junior Member
    Messages: 22

    I checked the wiring, its all in the proper locations (no one changed pinout) the right colors and positions are going to the proper places in the plugs, etc. The lights are grounded to the pump....I'm not sure what else to look for.

    Travis
     
  18. cubicinches

    cubicinches PlowSite.com Addict
    Messages: 1,412

    See page ten here:

    http://library.westernplows.com/westernplows/pdffiles/28561.04_052407.pdf

    The wires in your harnesses need to be configured for an HB-1 bulb. HB-5 uses the same connector at the bulb, but the wire locations are different... similar to what Arcburn mentioned. Same goes for the isolation module end. I know you mentioned that you've already swapped the blue and yellow at the module end, check the headlamp end.
     
  19. TMacie

    TMacie Junior Member
    Messages: 22

    Dieselss: no this isnt out of the blue, its always been like this on this truck. I haven't been able to figure it out.

    Cubicinches: The wiring looks right, but I'll try swapping the pins just to see what happens.

    Travis
     
  20. cubicinches

    cubicinches PlowSite.com Addict
    Messages: 1,412

    Another thing I'd look at is the wires where they go into the backs of the female sockets on the plug in harnesses (where the vehicle's factory plugs plug into). It's a hard black plastic socket, and they're not weather packed. Check where the wires go into the black plastic for even the slightest sign of any green corrosion. It's a fairly common issue on 26349 & 26354 harnesses, and the only fix is to replace the harness, or bypass the plug and hard wire it.