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used fisher installation, '02 F250

Discussion in 'Fisher Engineering Discussion' started by nichols, Oct 9, 2006.

  1. nichols

    nichols Member
    Messages: 47

    Hi guys,

    I recently purchased a 7' 6" Fisher MM plow (the two plug version) that was mounted to a '99 F350. I'm currently in the process of swapping the hardware and wiring harness over to my '02 F250.

    I bolted the push plates up last night, but I'm having some trouble figuring out where all of the wiring fits in. There are two blue plugs in the harness that have a red, orange, and blue wire in them. There is also a black plug with a green, yellow and blue wire.

    Is the deal that you disconnect the headlight wiring somewhere (that I haven't found yet), plug them into the blue plugs, and the black plug comes from some other source?

    Also, I see the purple wire coming out of the longer of the two blue plug harnesses - I assume I have to tap that wire into the turn signal wire of the passenger turn signal light. But, on the drivers turn signal light, I'm not sure I can find the grey and brown wires that supposedly are tapped on the drivers turn signal.

    I apologize for the basic questions. Also, I apologize in advance if the '99 harness is completely different than the '02 harness... :)


  2. nichols

    nichols Member
    Messages: 47

    Well, I made some progress.

    I (think) I have everything wired except the turn signal wires, and the switched accessory wire for the joystick. I didn't realize that the blue plugs mentioned above plug directly into the headlights, and the factory passenger headlight plug is not used. It didn't make sense until I was able to confirm that the factory passenger headlight plug is just tucked away and ignored. :)

    So, just for the archives, on the older harness that just uses relays and not isolation modules, the black plug snaps into the factory plug for the driver side headlight, and a blue plug goes to both headlights. My grey and brown wires both look close in color - I'd expect a brown color to be... well... more brown and less grey. ;)

    Tonight I'm going to try to pull the directional housings out and see if I can get to the wires a little easier to tap in. Is it just two screws on the bottom and pull it out, or am I missing something?

    By the way, sorry for the double topic - if someone wants to delete the other one, feel free.
  3. nichols

    nichols Member
    Messages: 47

    ALMOST there.

    Everything works with the plow hydraulics, and everything works with the wiring... sort of.

    As soon as I plug both plugs in, both directional lights come on solid, no matter what.

    The headlights come on when I turn the truck's headlights on (and the truck's headlights turn off when I plug the plow in), and the high and low beams seem to work ok.

    When I hit the right directional, it blinks, but exactly opposite the truck's directional (which I assume is related to the fact that the directionals on the plow are always on solid).

    When I hit the left directional, the headlights blink, but the left directional stays on solid with no change.

    I have a two relay setup in my wiring harness - if anyone can help, I'd really appreciate it.

  4. Yaz

    Yaz PlowSite.com Addict
    from NH
    Messages: 1,061

    Did you try Fishers web page to find a wiring diagram? I think you can find one there. When you buy one new it comes with one. You may find a close Fisher dealer and stop in say hi tell them what you are doing, most would be glad to help.
  5. nichols

    nichols Member
    Messages: 47

    Thanks, Yaz. I did try Fisher's website and found the diagrams - that's how I got as far as I did up until that point.

    I spent a bunch of time tonight with the multimeter and found the problem. In the directions (which is backed up by the diagrams), there is a brown wire that is supposedly spliced to the parking lights, and a grey wire that's spliced to the left directional.

    On this harness, those two are reversed. Swapping them solved my problem, after an hour or two of wire tracing, relay testing, and plug mapping.

    At least I know the harness backwards and forwards now.