Now that I am in the right area, I have 4 black wires and 1 yellow wires with 2 ends on it, what do these wires do" I want to test them for funcinalty as I will be resuing this section of the harness. My exisitng harness is a rats nest with splices everywere, and this one is in near immaculate shape
lighting
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Scoutboy74
Moderator
You'll need to narrow this down some. Colors alone don't mean much. Any circuit numbers still visible? What gauges are the wires? Maybe a well-focused pic would help us home in.
ronmc1954
Member
I think we still need to narrow this down, when you say connect to the cab, do you mean coming from the dash to the engine compartment? Or are they coming from the engine compartment to the cab or dash? Can you trace the wire to find the other end and find what it is connected to?
Ron
Ron
ronmc1954
Member
If I remember right ihc72 you have a pickup, but that should not matter much. Basically you should have:
1 taillight wire
1 backup light wire
2 turn signal wires
that accounts for 4 of them, I am not sure where you gas tank is, in a Scout there's a wire for that to.
You could pull a + wire from the battery and touch it to each wire and have someone watch the back and see what comes on.
Or you could pull the wires apart below the passenger taillight and use and ohm meter to trace the wire back to the front.
Now to connect to the bulkhead connector use a volt meter at the bulkhead connector. Turn on the taillights and find which one it is and connect to the "taillight wire" that you found with the previous instructions.
This is rather a down and dirty way to do it put it will narrow things down some so you can find where "all" the wires go.
I hope that helps.
Ron
1 taillight wire
1 backup light wire
2 turn signal wires
that accounts for 4 of them, I am not sure where you gas tank is, in a Scout there's a wire for that to.
You could pull a + wire from the battery and touch it to each wire and have someone watch the back and see what comes on.
Or you could pull the wires apart below the passenger taillight and use and ohm meter to trace the wire back to the front.
Now to connect to the bulkhead connector use a volt meter at the bulkhead connector. Turn on the taillights and find which one it is and connect to the "taillight wire" that you found with the previous instructions.
This is rather a down and dirty way to do it put it will narrow things down some so you can find where "all" the wires go.
I hope that helps.
Ron
ronmc1954
Member
If your reffering to a battery charger, just find a good ground and connect up the "-" clamp to it the use the positive clamp to touch the wire. That's assuming your lights are still installed in the body of the truck, if not you have to ground the taillight housing.
Just a warning do not connect the wire up and run to the back to see what happens. You need a helper or someway to see what is going on (dark garage) you don't want to burn something up, you just want to touch it, if say the taillight comes on then Mark the wire and move on to the next one.
Turn signals will be a little more difficult because they won't blink, they will look like a taillight. But they will be a little brighter than the tails, because they are the brake light also.
Ron
Just a warning do not connect the wire up and run to the back to see what happens. You need a helper or someway to see what is going on (dark garage) you don't want to burn something up, you just want to touch it, if say the taillight comes on then Mark the wire and move on to the next one.
Turn signals will be a little more difficult because they won't blink, they will look like a taillight. But they will be a little brighter than the tails, because they are the brake light also.
Ron
Scoutboy74
Moderator
Although the pic is a bit fuzzy, it looks like there is a circuit id number at least on the yellow wire. Any numbers that are still legible on the wires can be cross-referenced against the wiring diagrams and circuit id pages contained in the service manual for '69 thru '73 pickalls if you have one.
Ron - fuel tanks for the d-series pickups (not sure about t-alls) are located outside the frame rails under the cab on both sides.
Another wire that will be in the rear loom is for the license plate lights. One other one would be for the rear markers on either side.
Ron - fuel tanks for the d-series pickups (not sure about t-alls) are located outside the frame rails under the cab on both sides.
Another wire that will be in the rear loom is for the license plate lights. One other one would be for the rear markers on either side.
ronmc1954
Member
Correct me if I am wrong "74" but markers and license plate light would not come all the way back to the bulkhead, would it?
They would be tied to the taillight circuit. But as I said I am more familiar with scouts.
The fuel sender(s) May or May not be one of these wires, I am more concerned about hooking up 12v to a fuel sender, thats something that could be a costly mistake. I would suggest to trace down the fuel sender wire to make sure you leave that alone.
74 is right diagrams and id numbers takes the guess work out of it.
Ron
They would be tied to the taillight circuit. But as I said I am more familiar with scouts.
The fuel sender(s) May or May not be one of these wires, I am more concerned about hooking up 12v to a fuel sender, thats something that could be a costly mistake. I would suggest to trace down the fuel sender wire to make sure you leave that alone.
74 is right diagrams and id numbers takes the guess work out of it.
Ron
Scoutboy74
Moderator
Yeah ron, you're right about certain wires in the rear harness not running to or from the bulkhead. Didn't mean to cornfewz the issue. With sii's the wires for the license plate lights and the tail markers originate from a junction connector just forward of the rear bumper as they are essentially part of the tail light circuit. 1hc72 will still need to id and label those shorter wires.
It is probably too late now, but you should have just disconnected the wires from the back of the lights (brake, backup and license plate) on your original bed; marked which one was which with masking tape and taped them up in the frame rail.
Then, just connect them to the "light buckets" on the new bed -- the connectors to the "light buckets" are probably the same.
If the wiring in your 72 is stock, the wires should be green and there should be small numbers printed on the wires indicating the circuit --- the numbers match the numbers on the circuits in the wiring diagram in the service manual.
At this point, you probably need to make a "test" / "connector" wire. "switch on" a "circuit"; find which wire is "hot" (brake, turn signal, parking, backup license plate) and touch the wire to that wire and to a wire on the bed and see what happens -- until all the "circuits" work correctly...
If you or the po pulled / cut wires in the cab and / or engine compartment, good luck.
Then, just connect them to the "light buckets" on the new bed -- the connectors to the "light buckets" are probably the same.
If the wiring in your 72 is stock, the wires should be green and there should be small numbers printed on the wires indicating the circuit --- the numbers match the numbers on the circuits in the wiring diagram in the service manual.
At this point, you probably need to make a "test" / "connector" wire. "switch on" a "circuit"; find which wire is "hot" (brake, turn signal, parking, backup license plate) and touch the wire to that wire and to a wire on the bed and see what happens -- until all the "circuits" work correctly...
If you or the po pulled / cut wires in the cab and / or engine compartment, good luck.
Michael Mayben
IHPA Tech Moderator - Retired & No Longer Online
All the wiring on that "donor" bed appears to be jury-rig "trailer" wiring, it's not the oem wiring!! All that shit needs to be ripped out and reworked from scratch with a new harness fabbed that will interface with the oem "rear" harness that comes down the driver side of the frame rail.
You must get yourself a service manual!!! It will have everything you need for reference on this vehicle! And you are working with a pickup...which has already been butchered when the service body was installed no doubt...and nothing regarding a Scout II is applicable other than they both use wire anda battery! Even the bulkhead connectors are in completely different sequence/locations!
The actual schematic set for each platform series is broken into several units/pages...one for the basic cab, one for the "front-end", one for the "back-end", one for auxiliary/trailer /camper harness, etc. And the legends and standardized electrical practices for IH products are spelled out in detail.
There is nothing "unusual" about the cab-back wiring on a pickup/Travelall...it's straight-ahead wiring just like you would install when wiring a trailer frame from scratch. The license illumination pigtails off the tail light wire run, same for the side markers. Each light set "pigtail/socket" must have a proper ground, all light buckets must be grounded to the body, the body must be grounded/bonded back to the battery negative terminal, etc.
You must have a vom and know how to use it to trace wire runs, you must have a probe-type test light, you must have a fresh battery/fully charged, you must have a schematic to understand the wire runs, etc.
A cts 2303 is the service manual set needed for this vehicle.
You must get yourself a service manual!!! It will have everything you need for reference on this vehicle! And you are working with a pickup...which has already been butchered when the service body was installed no doubt...and nothing regarding a Scout II is applicable other than they both use wire anda battery! Even the bulkhead connectors are in completely different sequence/locations!
The actual schematic set for each platform series is broken into several units/pages...one for the basic cab, one for the "front-end", one for the "back-end", one for auxiliary/trailer /camper harness, etc. And the legends and standardized electrical practices for IH products are spelled out in detail.
There is nothing "unusual" about the cab-back wiring on a pickup/Travelall...it's straight-ahead wiring just like you would install when wiring a trailer frame from scratch. The license illumination pigtails off the tail light wire run, same for the side markers. Each light set "pigtail/socket" must have a proper ground, all light buckets must be grounded to the body, the body must be grounded/bonded back to the battery negative terminal, etc.
You must have a vom and know how to use it to trace wire runs, you must have a probe-type test light, you must have a fresh battery/fully charged, you must have a schematic to understand the wire runs, etc.
A cts 2303 is the service manual set needed for this vehicle.
Michael Mayben
IHPA Tech Moderator - Retired & No Longer Online
There is no "color" for the wiring except for maybe the wiper motor and the turn signal switch under the dash. All "feed" circuits/wire runs use a green color insulation with circuit id numbers printed on the ends. Grounds for the most part will have black insulation though not always. This is standard truck electrical system practice.
The schematics call out wire runs/"circuit numbers"! IH used their own proprietary circuit number system/nomenclature...thus the need for a service manual with schematics!
There is no color code for IH electrics except for those electrical components supplied by an outside vendor such as saginaw, indak, delco remy, etc. In that case the component color codes interface with wire run numbers in the schematics.
Because you have "color" in the wiring found on each truck bed, that indicates a juryrig on the pickup bed from the chopped frame.
The manufacturer of the service body supplied a wiring system for it which was to their manufacturing standards and also included an interface to mate with the truck manufacturer's wiring harness at the point where the body was installed on the chassis. That interface included documentation regarding "which" wire color on the service body interfaced with "which" circuit number on the cab/chassis.
Plain old "flat four wire" trailer wiring convention May be found here:
trailer wiring diagrams