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3 Plug Question

Discussion in 'Fisher Engineering Discussion' started by GSORK, Feb 14, 2009.

  1. GSORK

    GSORK Senior Member
    Messages: 128

    So what is the difference between 2 and 3 plug. which is a better system. Im looking at a used plow 8ft MM .
  2. fisher guy

    fisher guy PlowSite.com Addict
    Messages: 1,068

    deff. go with 3 plug. its a more reliable system and is now the norm ill let a more expierced person give u all the other benifits
  3. chcav1218

    chcav1218 Senior Member
    Messages: 954

    three plug is better and is what is on all the new plows
  4. Crash935

    Crash935 2000 Club Member
    Messages: 2,377

    2 plug harness if its a older truck that only ran 2 relays in the harness to switch the headlights. Easier and cheaper to troubleshoot and replace/repair.

    3 plug if its a newer truck. The wiring and computers in the newer trucks are "touchy" and the iso module helps without 6 relays which are a pain to troubleshoot.
  5. justme-

    justme- 2000 Club Member
    Messages: 2,138

    6 relays? My 2 plug harness has 2 relays, one to switch to plow lights and one to power them.

    I know the new computers can be touchy, but based on what's in my truck, I can remake the whole truck side harness from scratch in a couple of hours.
  6. Crash935

    Crash935 2000 Club Member
    Messages: 2,377

    Yup, 6 relays, had to go with 4 to get the dodges to work and 6 to get GM lights to work. Thats why everyone likes the iso mod, alot easier to plug in 3 or 4 harness' versues 30 wires into a block of relays.

    If your 2 relay harness is factory western/fisher then one relay is for low beams and the other is for hight beams.


    What truck are you putting this on?