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Isolation module

Discussion in 'Fisher Engineering Discussion' started by CHPL, Feb 23, 2007.

  1. CHPL

    CHPL Member
    Messages: 82

    I have 3 chevy silverado's. 2 HD 2500 and 1 1500. They are all 2003 or newer. I want to take the plow from the 2005, 1500 off and install it onto a 2001 2500HD other then truck side mounts, will the harness and module work? Any help on this would be appreciated.
  2. CHPL

    CHPL Member
    Messages: 82


    No one has any insight on this???
  3. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Your harness and module will work on the '01. Just the mount is different.
  4. Antnee77

    Antnee77 PlowSite.com Addict
    from RI
    Messages: 1,056

    The module will work, but the headlight harness is different for the 2001.
  5. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    As long as this is a 3 plug isolation module, your headlight harness will work too as both the trucks use the same head light bulbs (9006/9005). All you have to do is flip the configuration plug 180 degrees, since one truck is pos to excite and the other is neg to excite.
  6. CHPL

    CHPL Member
    Messages: 82

    more help

    So here's were I'm at now. I removed the module (4 plugs) and harness from my 2005 and transferred the wiring and module to the 2001. The harness plugged into the factory harness at the head lights and I spliced the turn, marker and DRL wires. When I plug in the plow the parking lights on the plow operates, but no low beams. The high beams, parking lights and turn signals on the plow work correctly. There is a connector in the harness right near the module with a dummy plug in it that has no wires, do I need a jumper there? Thanks
  7. Antnee77

    Antnee77 PlowSite.com Addict
    from RI
    Messages: 1,056

    Like I said, the headlight harness is different for the 01. It can be made to work, but you'll have to check out Fisher's website and study the schematics. I'd do it for you, but I have to go out and plow.
  8. Nascar24

    Nascar24 Senior Member
    Messages: 645

    Take B& B advice!


    AS B&B said check the configuration plug, probabaly have to swap the pins around, look at Fishers Tech Pages on thier web site, compare the configuration plug diagram for the 05 and compare to the 01, bet its a simple switch of the wires.

  9. gmcsierra1500

    gmcsierra1500 Senior Member
    from CT
    Messages: 151


    I had the same problem on my 2000 1500 everything worked but the low beams on the plow, i changed teh headlight harnesses out and it fixed the problem so like Antnee77 said you probly have the wrong light harnesses
  10. chaseatg

    chaseatg Member
    Messages: 94

    Fisher does not use a Config plug on that GM truck, so put that out of your mind.
    You have the wrong headlight harnesses. For a 2001 GM silverdao you need Fisher Part # 26360 and 26361 harnesses to make your lights work properly.
  11. pyro29

    pyro29 Member
    Messages: 74

    Thanks for the info

    I had the same problem on a 2000 Silverado. Had all the correct harnesses and module. Ended up having to hook the RF low beam as indicated (common to ground and low to positive) and the LF low beam plus both high beams connected with reverse polarity. Everything works great now. I was very happy to hear that this has happened to someone else, thanks to all who had replys in this and the other threads for giving me the idea to ploay around with the polarity...
    Last edited: Dec 9, 2007