wiring help

Discussion in 'General IH Tech' started by mudturk37, May 11, 2009.


  1. mudturk37

    mudturk37 Farmall Cub

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    the Scout that I recently purchased had a terrible wiring job to the rear and the tail lights were not even installed....the previous electrician had ran house wire from the front to the rear and used wire nuts to connect everything

    in the interest of saving money on a project that may never see the road, i have decided to try rewire the entire rear harness from scratch

    i'm trying to follow this wiring diagragm

    http://www.binderblues.com/main/tech_imgs/rearharn.gif

    i'm ignoring the interior dome lights and all i need to wire are rear side marker lights, tail lights, brake lights, reverse light, and license plate light, 5 circuits from my count......i didnt forget about the fuel sending unit either

    coming out of the front firewall is a cluster of 7 wires, 5 black and 2 green which i presume to be grounds (this might be a good time to mention i am an amateur electrician as well as amateur mechanic) :banana:

    i've got plenty of 16 gauge wire ready and i've practiced my soldering skills.....i've also got enough wire protector sleeve and heat shrink tubing to wire a whole fleet of Scouts

    i guess i just need a place to start.....advice / tips / help?

    should i start with the drivers side marker light and work my way around and up to the front? start at the front and work my way back? i'm kinda confused how i'm going to splice everything together without connectors??? for some stupid reason i also thought i could ground everything directly to the body but then what are the two grounds included in the cluster of wires (if in fact they are grounds in the first place)

    i'll finish by saying that i have a degree in mechanical engineering so i'm at least confident that i can accomplish about anything if i try so i don't imagine wiring some tail lights would be too hard to figure out....i just need a kick in the right direction

    :beer: :scout:
     
  2. trailerjack

    trailerjack Farmall Cub

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    When you rewire, what type of wire are you going to use....I saw this tinned copper wire at the store the other day and regular copper wire....


    Which one is better, and what are the benefits?


    Good luck on the rewire, I am about to do the same, and I am just taking my time researching, and researching more.
     
  3. Russ McLean

    Russ McLean High Wheeler

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    Do not "presume" anything. Most of the wires under the dash of my 75 Scout 2 are green...

    The wiring in a 1961 Scout is very different than the wiring in a 1980 Scout. We will need a couple of clues. Get a test light or voltmeter and verify what voltage is on each wire.

    Temp, oil pressure and fuel level (assuming that the Constant Voltage Regulator (CVR) is working will have pulsing 12 volts that averages to about 5 volts. Use a resistor to ground (any where from 10 to 40 ohms) and see which gauge moves.

    Ignition comes on when the key is in the "run" position.

    Accessory comes on when the key is in the "accessory" position.

    Same tests for the light wires.
     
  4. LeeC

    LeeC Guest

    You've gotta love to hate the ALL GREEN WIRING these trucks have :censored:. Makes tracking the other end down next to impossible at times. Proper test equipment is a most. I'm going the Wiring Kit route on my project. Something like Painless with all the wires labeled. Best of luck with your project. :)
     
  5. Eric VanBuren

    Eric VanBuren Lives in an IH Dealership

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    The green wires are the ones for the dome light. The marker, running, and license plate lights are all the same circuit. Then you have the backup lights, L turn/brake, R turn/brake, and the fuel sender.

    If you have the stubs of the OE wire connected to the bulkhead connector the cir numbers are as follows. #36 fuel level, #56 L turn/brake, #57 R turn/brake #68 tail #71 back up. The #'s are printed on the wire near the connector in white.

    IH does use color coding green 18ga green, black 16ga, white 14ga, red 12ga, blue 10ga.

    Jack, the tinned copper wire is commonly used in marine applications, it is more corrosion resistant than standard copper wire.
     
  6. trailerjack

    trailerjack Farmall Cub

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    Thanks Eric, I found some on sale really cheap 16 gauge, and wanted to make sure I could use that just as well.

     
  7. mudturk37

    mudturk37 Farmall Cub

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    thanks a ton guys, this will really help me get started

    i really need an automotive wiring for dummies book :cornfused:
     
  8. Doc Stewart

    Doc Stewart Content Team Staff Member Moderator

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    For your rear harness:
    #16 wire
    Right turn / Left turn / tail including clearance and license plate / reverse
    #12 wire
    Blue for the trailer connector for electric trailer brakes
    #14
    Red for charging a trailer battery.

    Ground all lights to the body.
    Use a ground strap from body to frame and from frame to battery as well as engine block to battery.

    For your front harness:
    #16 wire
    Right turn / Left turn / clearance /
    If you use relays for your headlights and driving/fog lights, you can run # 16 wire to the relays. Use #12 from battery to relay to lights.
    If you don't use relays, run #12 wire from the switches to both.
     
  9. mudturk37

    mudturk37 Farmall Cub

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    i dicked around and didn't get to tear into this too much

    i inspected the connection at the firewall and didnt want to tear into the dash this late in the evening

    one of my 5 black wires goes somewhere down to where the transmission used to be so i would guess that is the backup lights with a reverse sensor on the trans?

    the other wires are all on a 6 pin connector at the firewall........is the location on the connector a clue as to what they are or not?
     
  10. Doc Stewart

    Doc Stewart Content Team Staff Member Moderator

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    Get the wiring diagram for your truck - it is posted on here somewhere. Standard advice is to buy the shop manual from any light line dealer or binderbooks.com.
     
  11. mudturk37

    mudturk37 Farmall Cub

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    after some closer inspection, i was able to read the circuit # on all but one of the wires and match them up with the wiring diagram....the last wire was a simple process of elimination

    two new questions

    at the firewall connector, there are two large gauge wires that screw/clamp to the connector.....what are these for?

    also, what is the best method for dealing with the two wires for the dome lights that will not be hooked up? just leave them hanging....snip them clean off...what?
     
  12. Doc Stewart

    Doc Stewart Content Team Staff Member Moderator

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    The two larger wires at the firewall connector are the in and out from the alternator to the amp gauge and back to the starter solenoid 'bat' terminal to charge the battery.

    1. Clean the firewall connector contacts well then assemble with dielectric grease. Those large wires carry the atlernator output. A little corrosion creates lots of heat - enough to burn.

    2. Eliminate the firewall connector. It is only there for assembly line purposes. Remove both parts; put a grommet in the hole, run the wires directly using crimp connectors or solder joints with shrink tubing.

    3. If you upgrade the alternator for winching or lots of lights, eliminate the amp gauge and those heavy wires because they are not heavy enough to carry any extra load. Use a volt meter reading an ignition controlled circuit instead.
     
  13. mudturk37

    mudturk37 Farmall Cub

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    worked til 4:30 in the morning last night and got the wiring harness made.....worked some today wiring all the bulbs......should be able to get everything mounted and tested soon :beer:
     

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