1. Welcome to PlowSite. Notice a fresh look and new features? It’s now easier to share photos and videos, find popular topics fast, and enjoy expanded user profiles. If you have any questions, click HELP at the top or bottom of any page, or send an email to help@plowsite.com. We welcome your feedback.

    Dismiss Notice

2 plug to 3 plug HELP

Discussion in 'Fisher Engineering Discussion' started by FordFisherman, Apr 5, 2011.

  1. FordFisherman

    FordFisherman PlowSite.com Addict
    from 06611
    Messages: 1,594

    Switched my MM1 from 2 plug to 3 plug, all new wiring with the exception of the battery wiring and solenoid (solenoid was new in the fall). Iso Mod is new as well. Checked all fuses, 12v to red wire in control harness but no red light, no plow function and truck lights do not switch over to plow. Double and triple checked all connections, no luck. Plow functions on my other truck and this truck won't work the other plow so its definitely truckside. Any ideas?
     
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Which all lead to the system not having ground. Check your black/orange wire and also be sure it's getting though pins 2 and 7 in the grill plug as that's what introduces ground to the system when the plow is connected.
     
  3. FordFisherman

    FordFisherman PlowSite.com Addict
    from 06611
    Messages: 1,594

    Ok, will check. Thanks.
     
  4. FordFisherman

    FordFisherman PlowSite.com Addict
    from 06611
    Messages: 1,594

    No ground at 2 or 7. Using my Fluke meter, red to 12v, black to 2 or 7 showed no voltage. Is this the correct procedure?
     
  5. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Should have ground on pin #2. Since you don't, then you need to go over the black/orange wire to see where the issue is. Be you have it plugged into the mating connector on the battery cable harness and it shows ground there.

    If you have ground on pin #2 and you use a jumper wire to jump #2 and #7 together the system (controller) will power on if it's functioning correctly.

    Assuming we're working with a 4 port Iso follow the diagram on page 18 here to trace the system down. Makes it easy then.
     
  6. FordFisherman

    FordFisherman PlowSite.com Addict
    from 06611
    Messages: 1,594

    3 port 29070-1. Will try the jumper now. Thanks
     
  7. FordFisherman

    FordFisherman PlowSite.com Addict
    from 06611
    Messages: 1,594

    No power with jumper.
     
  8. FordFisherman

    FordFisherman PlowSite.com Addict
    from 06611
    Messages: 1,594

    Fixed it. Bad ground splice. Thanks.
     
  9. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    In the battery harness? Been seeing more and more of those.
     
  10. FordFisherman

    FordFisherman PlowSite.com Addict
    from 06611
    Messages: 1,594

    No, the wire i spliced for the ground was silver core (only black wire I had). I replaced it with cooper strand and that was the issue all along. Go figure.... Not sure why it makes a difference but I'm glad its sorted out. Thanks for your help.