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Tracing back horn wiring to cab

Discussion in '1st Gen. Tacomas (1995-2004)' started by 96Taco, Aug 22, 2011.

  1. Aug 22, 2011 at 10:33 PM
    #1
    96Taco

    96Taco [OP] Well-Known Member

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    When I purchased my truck I noticed that there are no wires connecting to the horn. I want to fix this and wire it up. My problem is Im not sure where the horn wire leaves the cab from. Does it come out on the passenger side "Cowl wire" or the driver side "engine wire"?

    I've tried tracing it from horn relay, but there is a LOT of wires down there. Any help would be great.
     
  2. Aug 23, 2011 at 1:40 AM
    #2
    G scott04

    G scott04 ...

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    87% percent sure its the drivers side wires...
     
  3. Aug 23, 2011 at 6:35 PM
    #3
    96Taco

    96Taco [OP] Well-Known Member

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    Haha thanks, that's 87% more sure than I am. I will start looking there.
     
  4. Aug 23, 2011 at 6:49 PM
    #4
    Miata Tech

    Miata Tech Well-Known Member

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    Probably should look at a wiring diagram. I doubt fhe horn circuit works the way you think it does
     
  5. Aug 23, 2011 at 7:17 PM
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    G scott04

    G scott04 ...

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  6. Aug 24, 2011 at 10:17 AM
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    96Taco

    96Taco [OP] Well-Known Member

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    Thanks guys. I studied all those pages very hard before posting , but could not specifically trace the horn wiring out of the cab.
     
  7. Aug 24, 2011 at 10:21 AM
    #7
    Greensystemsgo

    Greensystemsgo Clean 1 owner with low miles.

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    for mine, a 99, the horn works, i have wires, but theirs a break SOMEWHERE. the wire leaves the horn, goes to the passenger follows the fender towards the firewall, and about then i gave up. i reccomend just pulling the dash, and running your own fresh wire, as it goes through numerous circuits, and you cant just easily run it and what not, just run the wire from the wheel through the firewall wherever, and attach securely.
     
  8. Aug 24, 2011 at 11:12 AM
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    jbrandt

    jbrandt Well-Known Member

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    from the above linked wiring diagrams, it looks like the horn wire(s) enter the cab on the upper driver side (?).

    So you don't see ANY loose wires near the horn?? Sounds fishy that someone would entirely remove the horn wires.

    There are a couple harnesses near the horn assembly, I'd start by pealing back the plastic covers on those wire bundles and see if you see a cut wire. Then enlist the help of a buddy and have them lay on the horn as you use a volt meter to test that wire (negative lead on a ground, positive lead on wire).

    horn off = no voltage, horn on = voltage (not sure how much, though) and you found your horn wire.

    good luck!
     
  9. Aug 24, 2011 at 11:27 AM
    #9
    96Taco

    96Taco [OP] Well-Known Member

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    Thanks guys. Yep the plan was to trace back the horn wiring inside the engine bay and try to find where he cut them. Just wanted to know which way to start tracing back
    . As you can see from that diagram "Electrical Wiring Routing 1" the horn itself plugs in to a wire that looks like it goes around the whole engine bay. Will try running from the engine side first. If I can't find anything at all, might just run my own wiring. But that would be a minor PITA.
     
  10. Aug 24, 2011 at 12:37 PM
    #10
    jbrandt

    jbrandt Well-Known Member

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    running your own wire from the steering wheel would be more than just a *minor* PITA, IMO.

    I can't imagine that someone would completely remove that ONE wire. There's got to be a cut wire there somewhere! It's probably just hidden in one of the harnesses.

    You should be able to figure out what color the wire from the steering wheel is (using the wiring diagram - they have wire colors IIRC), and trace it FROM the steering wheel, or at least the body ECU.

    According to the above linked wiring diagram, the wire from the horn switch (steering wheel) is green with red. The wire FROM the ECU to the horn (low and high) is black.
     
  11. Aug 25, 2011 at 12:38 PM
    #11
    96Taco

    96Taco [OP] Well-Known Member

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    Yep thats the plan. Trace it out from the relay. Just so many god damn wires down there that that can get tricky. I see in the 1998-2000 fsm which is closer to my model, it goes to a horn relay (in junction box 1) not body ecm like the 2003 fsm. Hopefully that simplifies things somewhat, but there is still going to be a shitload of wires coming out of that J/B. It looks like it leaves cab vire engine main wire (drivers side).
     
  12. Aug 25, 2011 at 1:05 PM
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    jbrandt

    jbrandt Well-Known Member

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    yeah, many times I'd rather hit myself in the balls with a claw hammer, than troubleshoot electrical problems...
     
  13. Oct 10, 2013 at 11:00 AM
    #13
    oldguy128

    oldguy128 Active Member

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    FUNNY READING THIS NOW, just been through this stuff
     
  14. Oct 11, 2013 at 7:05 AM
    #14
    96Taco

    96Taco [OP] Well-Known Member

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    I ended up just running new cables from the horn to the cab.. picked up a new relay and wired it all in. That was a very long time ago tho ha
     
  15. Sep 17, 2016 at 10:09 AM
    #15
    RysiuM

    RysiuM Well-Known Member

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    Sorry for bringing up this old thread, but I need info about the factory horn circuit for 95 4x4 Tacoma. I have Haynes repair book but all electrical diagrams in there do not show horn circuit.

    I know there is a relay somewhere under the dash (I hear it clicking) and 15A fuse in the engine compartment fuse box (the same fuse is used also for emergency lights). This the relay under the dash is powered via this fuse (when I removed the fuse, the relay does not click anymore). This is all I know and the circuit seems to be simple one, but I would like to know for sure. Does anyone has a copy of the page with this part of diagram? Any format is good: pdf, jpg, gif or bmp.
     
  16. Sep 17, 2016 at 1:33 PM
    #16
    tan4x4

    tan4x4 Well-Known Member

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    I have a '99 FSM, and it just shows a single black wire going from the relay, to the horn itself. The horn's case is the ground.
    Its about as simple as an automotive circuit gets.

    On mine, that wire emerges from the main harness, just below the passenger-side head light, and runs a short distance (passenger-side towards driver-side) to a connector for the horn. I can see that wire (with its shroud) if I lay on the ground, by the front-right corner of the bumper, near the coolant reservoir and look up toward the head-light housing.

    Hope this helps
     
  17. Sep 17, 2016 at 5:18 PM
    #17
    RysiuM

    RysiuM Well-Known Member

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    Thanks. It looks like the same is in 95. Actually I found 2001 diagrams with dual horn and from your description and my observation it looks like it is the same (minus dual horn).

    [​IMG]


    A couple years ago I did simple mod and I replacec single "muu-muu" horn with Hi/Lo"harbor freight" horn set and it seemed to work well. Till now. So I thought that maybe the horn current was going not through relay but by steering wheel. It turned out that both HF horns rusted through and relay and all wiring is OK. Now I'm replacing HF POS with FIAMM Hi/Lo set and I hope they will last longer. If not, then I will go for OEM Toyota horns (from Highlinder). I just wanted to be 100% sure I know what I'm doing.
     
  18. Sep 17, 2016 at 9:55 PM
    #18
    tan4x4

    tan4x4 Well-Known Member

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    I hated the meep-meep single 'horn', so I replaced it with dual horns from a 93 LS400. I try to stay with Toyota/Lexus parts as much as I can when I do upgrades. Did the same for my Corolla :D
     
  19. Sep 17, 2016 at 11:14 PM
    #19
    RysiuM

    RysiuM Well-Known Member

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    Do you have part numbers? Toyota horns I found are about 50 dollars a piece. I'm not ready to put 100 dollars into horn upgrade.
     
  20. Sep 18, 2016 at 9:18 AM
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    tan4x4

    tan4x4 Well-Known Member

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    The part numbers are:
    86510-50060 (Low) and 86520-50060 (High)

    I just got them at a pick-n-pull for $20. 91-94 LS400 all have the same horns.

    Also, I think that the 01-04 Tacomas have similar style horns that are much better than the ones on the earlier 1st-gens.
     
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