2019 F350 with Fisher XV2 plow. One headlight out.

Discussion in 'Truck & Equipment Repair' started by Kuchocki, Feb 10, 2020.

  1. Kuchocki

    Kuchocki Junior Member
    Messages: 15

    I have a plow with one headlight out. Switched to the other side of the plow, bulb works. Unplugged the plow from the truck and the opposite light on the truck went out. So I tried finding a fuse that controls it. Not listed in the manual. Google is coming up with nothing. What controls the passenger side truck light? Is there a fuse? It was so much easier when the manual told you where to look? Anybody have the wiring diagram for the 2019 F350 headlights?

    Thanks.
     
  2. cwren2472

    cwren2472 PlowSite Fanatic
    Messages: 7,635

    Is this new and still under warranty? If do, I'd let the dealer handle it.

    If not, see if there is a piece like the photo below attached to ports b&c of the isolation module. If there is, remove it and plug the harness back in then retry the lights. It likely has that harness, doesnt need it, and its burnt out.

    Screenshot_20200211-071229_eBay.jpg
     
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  3. OP
    OP
    Kuchocki

    Kuchocki Junior Member
    Messages: 15


    It's new, and wasn't sure if it was in the truck or on the plow harness. I will bypass that harness and see what happens.
     
  4. OP
    OP
    Kuchocki

    Kuchocki Junior Member
    Messages: 15

    I bypassed the light harness and went to the truck wiring and the light came on. So there is a short in the plow harness. Off to the plow dealer to locate the problem wire.
     
  5. cwren2472

    cwren2472 PlowSite Fanatic
    Messages: 7,635

    With the plow connected and lights on, unplug the 11 pin plow light harness. Then plug it back in. If the lights stay functional after 3 repetitions, then you don't need that relay harness and can ignore the fact that you removed it and it doesn't need to go back to the dealer (though you certainly can if you want.)
     
    Last edited: Feb 11, 2020 at 1:45 PM
  6. cwren2472

    cwren2472 PlowSite Fanatic
    Messages: 7,635

    Officially all models of Ford SD from 2017-2019 are supposed to require that piece but most actually don't.
     
    Last edited: Feb 11, 2020 at 1:45 PM
  7. OP
    OP
    Kuchocki

    Kuchocki Junior Member
    Messages: 15

    I don't have that piece. Just the long harness wired to the plow. Wish it was as simple as popping that out.
     
  8. cwren2472

    cwren2472 PlowSite Fanatic
    Messages: 7,635

    Huh? I'm confused - what did you disconnect then to get the truck lights back on?
     
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  9. OP
    OP
    Kuchocki

    Kuchocki Junior Member
    Messages: 15

    A long harness about 6 feet long that runs along the rad to the far side of the truck where the iso module is. It has the blue connectors but it is much longer than what you have in the pic. Unless there was another connector that I couldn't see tucked behind the shrouds.
     
  10. Western1

    Western1 PlowSite.com Addict
    from MI.
    Messages: 1,775

    The harness that Cwren showed would be connected right in front of the module. Short harness
     
  11. Western1

    Western1 PlowSite.com Addict
    from MI.
    Messages: 1,775

    When you disconnected that harness did you plug truck harness back in?
     
  12. cwren2472

    cwren2472 PlowSite Fanatic
    Messages: 7,635

    I'm still confused - which of the 2 photos below does your setup look like?

    p2.jpg

    p3.jpg
     
  13. cwren2472

    cwren2472 PlowSite Fanatic
    Messages: 7,635

    From your description, it sounds like the second photo, but if that's the case, the only way you could have disconnected that and gotten the lights back on would be to totally remove the harness from the truck headlights which on that truck should have necessitated removing both of them entirely.

    (also, ignore the fact that the connectors are not fully seated in the photo)
     
  14. timboy

    timboy Senior Member
    from Ny
    Messages: 112

    That is interesting information,we have been installing them on all the new quad headlight super duties and have had multiple soft start module failures.
    Was this learned information or something passed on by tech support?
     
  15. cwren2472

    cwren2472 PlowSite Fanatic
    Messages: 7,635

    Learned - just our own unofficial experience
     
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  16. cwren2472

    cwren2472 PlowSite Fanatic
    Messages: 7,635

    Somewhat unrelated, but we've also run into 2 or 3 vehicles that will lose a light with or without the soft-start - for whatever reason, those particular vehicles will work ok without the soft start so long as the headlight switch is in the "AUTO" position, but not on manual.
     
  17. timboy

    timboy Senior Member
    from Ny
    Messages: 112

    Interesting,I'll have to start documenting what the particular failure was that led to the return and what setting the headlight knob is in.
     
  18. cwren2472

    cwren2472 PlowSite Fanatic
    Messages: 7,635

    I might not have been clear, but those situations were ones where it was cutting out the headlight immediately after install, not ones where the soft start module had failed.
     
  19. unhcp

    unhcp PlowSite.com Addict
    Messages: 1,325

    If you had a 19 ford that keeps killing the soft start relays, is there a fix?
     
  20. cwren2472

    cwren2472 PlowSite Fanatic
    Messages: 7,635

    Beyond not using it, not that I know of. It hasn't happened to us yet where a truck that required the module has killed one.

    Our practice now is the check every truck during install as I described above to determine if the soft start module is required. In the few cases where a light goes out with or without the module, we inform the customer of the issue and explain that should they have the lights on manual, that they need to be turned off or turned back to AUTO prior to unplugging the plow. I suspect using the lights in manual is fairly uncommon anyway.
     
    Last edited: Feb 14, 2020 at 11:37 AM