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unimount head light wiring question

Discussion in 'Western Plows Discussion' started by cowboybob, Nov 30, 2015.

  1. cowboybob

    cowboybob Junior Member
    Messages: 7

    First time to post. I am moving my 6.6 unimount plow from my 2003 wrangler to my 1985 toyota pickup. How do I deal with the positive and negative commons? I do not want to hack up my wire looms and I do not want to use toggle switch. Someone on this forum a few years ago stated all that was necessary was to flip the wires. I would like to see a diagram please.

    I also have the jeep wrangler mount kit to sell. Thanks so much.
     
  2. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,946

    Does the jeep or yota have negative switched lights? Or are they positive switched?
     
  3. cowboybob

    cowboybob Junior Member
    Messages: 7

    Thanks for such fast response. The yota is constant positive when head lights are turned on, the ground is switched for high and low beams. The plow lights are always grounded and power is provided to the high or low beams.
     
  4. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,946

    Might want to double check that.
    And is it only one sealed beam headlight?
     
  5. cowboybob

    cowboybob Junior Member
    Messages: 7

    only one sealed beam.same kind of head lights on both the jeep and the yota.this harness worked fine on the jeep. three prongs on all lamps. on the jeep one prong is always grounded and power switches the beams. on the yota one prong is always 12V and ground switches the beams.
     
  6. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,946

    I'm going to say no it won't work.
    Trying to take a positive switched system and adapt it to a neg switched system is gunna take some work.
    Might just be easier to add a switch and relay for the plow lights
     
  7. cowboybob

    cowboybob Junior Member
    Messages: 7

    Thanks, I will let you know how I make it happen. I was just not wanting to reinvent the wheel. Thought someone had already figured it out and I could save some time. Maybe someone else will chime in. In a old thread from 2011 Philbilly2 acted like he knew the secret.
     
  8. redneckwheelman

    redneckwheelman Junior Member
    from harris
    Messages: 19

    i just went threw this when i put a 1990s chevy unimount wire harness in a 2002 chevy. it was kinda a pain to make work, but how many relays does your wiring harness have?
     
  9. redneckwheelman

    redneckwheelman Junior Member
    from harris
    Messages: 19

    if you have 2 relays youll have to go to the auto parts store and get two addition relays.
    so with how the jeeps wiring harness was probably set up was a power source from the park lights into either 86 or 85 and the other 85 or 86 was a constant ground to complete the circuit and excite the coil. then at teminal 30 your original 12 volt input from your truck headlight was hooked to there and at 87a was the return to the truck headlight and 87was to the plow.

    but since its a switch ground truck you are putting it into you have to rework the connections at the relays, first with the 2 truck side ones the wiring for them should stay pretty much the same but the 87 or 87a terminal that wouldve been the plow headlight wire will have to get moved to the new relay terminal 87 or 87a. then from the open terminal on the old "truck side relay" you will be running a jumper to terminal 85 or 86 on the new relay. and you will have to run a power wire from the park light wire to the new relays terminal 85 or 86. and lastly a constant 12 volt wire from the battery to the terminal 30.

    confused yet? lol :dizzy:
    basically what your doing is taking the grounded output from the truck lights and having your first two relays "truck side relays" have a grounded trigger and a grounded output,
    then the grounded output from the first relay is what completes the second relays coil to energize it to send power to the plow lights.

    your best bet would be to find a plow wiring diagram for both of them and study it and figure out whats differnent.

    i know i had to also switch the wires in the plow harness that plugged into my truck lights because it was back feeding the passenger side bulbs.
    it might take some trial and error but it can be done,
    if you need to look at more relay diagrams i founf them on the12volt website
    hope i didnt confuse you more then you already are with it

    relay.jpg
     
  10. cowboybob

    cowboybob Junior Member
    Messages: 7

    thank you redneckwheelman. I was thinking that I might need to add two more relays. Had to take the plow off for now as I need the truck for a fencing project. Will let you know how it turns out when I can get back to it.
     
  11. Philbilly2

    Philbilly2 2000 Club Member
    Messages: 2,556

    I'm here now.

    I think what I commonly refer to is when guys cant get their headlights to work and they start cutting and splicing. You can flip plugs over and get a negative common to act as a positive common.
     
  12. Philbilly2

    Philbilly2 2000 Club Member
    Messages: 2,556

    I have read this a couple of times and I am a not sure if it is all the beer I have consumed or what.

    Are your headlight connection plugs for both trucks the same plugs?
     
  13. Randall Ave

    Randall Ave PlowSite.com Addict
    Messages: 1,948

    Look, you don't have DRLs. Just get a 30 amp rated on off on toggle switch, and wire it into the harness. Just turn on your parking lamps, and turn on the toggle switch.
     
  14. Philbilly2

    Philbilly2 2000 Club Member
    Messages: 2,556

    Hence my previous post....
     
  15. cowboybob

    cowboybob Junior Member
    Messages: 7

    I prefer not to hack into my wiring and adding more wires going back and forth through the firewall. This toyota is all original. So to answer Philbilly2, the head light plugs are the same on both the jeep and the yota.
     
  16. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,946

    You honestly only need 2 wires, and they can be 16 gauge or 18.
    And you wouldn't be "hacking" into your trucks factory wiring.....but your just not wanting to listen Linda......
     
  17. Randall Ave

    Randall Ave PlowSite.com Addict
    Messages: 1,948

    I'm out, he's been screwing with this for more than a week, and what you said.
     
  18. Philbilly2

    Philbilly2 2000 Club Member
    Messages: 2,556

    Do you have DRL on the Jeep or on the Toyota?
     
  19. cowboybob

    cowboybob Junior Member
    Messages: 7

    No DRL. Thank you guys for all your responses.