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3 port ISO or 4 port ISO?

Discussion in 'Fisher Engineering Discussion' started by Jt13speed, Dec 17, 2008.

  1. Jt13speed

    Jt13speed Senior Member
    Messages: 366

    Whats the difference between the 3 port ISO and 4 port ISO module for a fisher wiring harness? And does have anything to do with the plow being 2 plug or 3 plug setup?

    A friend of mine wants to wire up his 02' F250 superduty for the MM1 fisher plow they have at laying around at work. He went to the fisher dealer to get a price for wiring and truck side frame, but wasnt to impressed by the $1400 they wanted for it.

    I found a fisher wiring harness on ebay and the numbers match up with the ones for an 02' superduty on the fisher website. Im just not sure if it being a 4 port ISO will make a difference if it will work with this plow setup or not.
     
  2. Jt13speed

    Jt13speed Senior Member
    Messages: 366

    bump...hello anyone got input on this?
     
  3. Doakster

    Doakster Senior Member
    from Maine
    Messages: 650

    A 4 port module will have 3 plugs on the truck and plow harness.

    A 3 port module will have 2 plugs on the truck and plow harness.

    The MM1 probably has 3 plugs on it so you'll most likely need a 4 port module, if you need one I actually have a spare for a ford that I took off my truck and would sell it rather reasonably.
     
  4. Jt13speed

    Jt13speed Senior Member
    Messages: 366

    Sweeet thanks man thats the info i was lookin for. Do you have all the wiring harness with that to and how much $$ you thinkin?
     
  5. RepoMan207

    RepoMan207 PlowSite Fanatic
    from Maine
    Messages: 5,039

    wait a minute.. you can do either of them either way......atleast you can on a GM.....I think green label is GM, and white label is Ford, double check which is which with the three and four, and which harness to use before you go buying anything, you may get an ugly surprise.
     
  6. RepoMan207

    RepoMan207 PlowSite Fanatic
    from Maine
    Messages: 5,039

    26314 & 26400 iso module is for the Ford, which actually a white label module.
     
  7. RepoMan207

    RepoMan207 PlowSite Fanatic
    from Maine
    Messages: 5,039

    which is a 4 port iso....
     
  8. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,993

    But what's is the plow? Two or three plugs that is what makes the difference. DD is notorious for rotting and corroding harnesses, check used stuff well.
     
  9. Doakster

    Doakster Senior Member
    from Maine
    Messages: 650

    If the plow is a 3 port/plug harness, Than 26400 iso module will be the one. As stated this is a 4 port "white label" for Fords. This is the one I have sitting around, it came of my 03 F-350.

    The green label is for GMs, the green label modules are for trucks that have day time running lights

    But I'm going to put money on the plow harness being a 3 plug due to the fact it's a MM1, it's too old to be a two plug harness.
     
  10. Doakster

    Doakster Senior Member
    from Maine
    Messages: 650

    I'll send you a PM
     
  11. FordFisherman

    FordFisherman PlowSite.com Addict
    from 06611
    Messages: 1,613

    Related question but slightly off topic: The wiring for a MM1 and MM2 is different but how about the frame itself? If I had a truck w MM1 frame and wiring, all I would need to do is change the iso module and harness and a MM2 setup would work, correct?
     
  12. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    The old ones were two plug (relay systems), and then you had/have the current three plug that use either the 3 or 4 port Iso module. But you also have a modern TWO PLUG 3 and 4 port, but those are only on the xtreme vee's and XLS that use the multiplex wiring system.

    Confused yet? :D

    First thing is to find out for sure if the plow is 2 or 3 plug. And then you'll know what you need, and need to do.
     
  13. Jt13speed

    Jt13speed Senior Member
    Messages: 366

    Oh man you guys are awesome. I havnt had a chance to look at the plow yet, but today i will because right now its snowing like crazy here!!

    p.s. Thanks Doakster i got your PM, I will check with my buddy this afternoon and get back to you.
     
  14. Doakster

    Doakster Senior Member
    from Maine
    Messages: 650

    Never underestimate B&B for an answer:D
     
  15. Jt13speed

    Jt13speed Senior Member
    Messages: 366

    Well after a pretty long day, i got to check out the plow and its a 2 plug! Like B&B said, ends up the plow is an older model with the relays. So does this mean that it will not work with a 4 port ISO harness?? And to add to that some idiot rigged it with a 7 way trailer plug for one of the connections, so even if we got a harness we would have to do some chopping to it. Well what do you guys think...and thank you for all your help!
     
  16. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,993


    You may have to replace the plow side harness and lights unless you find someone to wire an older harness set up in to it. This can be tricky if you don't understand it, also the parts are hard to find if you don't know what to look for because there are no instructions for your vehicle as DD never supported it for the older relay system.. A LOT of experience helps.
     
  17. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Two different way you can go about this.

    1) Either wire the truck for the two plug relay setup that the plow is configured for. Yes they are still available for an '02 super duty for either the sealed beams or composite style lights.

    2) Or change the plow side over to the newer three plug style Iso system and then use your choice of either the three port, or four port Iso system on the truck side.

    The two plug relay setup would be the least expensive way, but the Iso setup would be the least obsolete and the most reliable. Although at a much more elevated cost.

    But it's your choice. :waving: