Wiring Harness Path Across the Rear of a 79 FJ40

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Oct 24, 2015
Clarksville, TN 37043
My rear wiring harness was butchered by a PO during the installation of a trailer connection. I'm trying to restore the harness and routing to get it as close to factory original as possible.

Below is the only helpful photo I have of the right rear corner of the FJ40 that shows the routing of the harness down the right side of the frame then over the round cross member and then through a recess in the top of the rear corner frame brace to the right rear tail light.

I don't have any photos that shows the path of the harness across the rear of the FJ from the right tail light to the left tail light.

My guess is that the harness was routed above the frame in the space between the tub and the frame. Is this correct or did Toyota route it under the frame?

If anyone has photos of the factory correct routing I'd appreciate it if you would post them.


79 FJ40 Rear Harness.jpg
Might be relevant.

On my '45 the rear harness starts on the PS of the fire wall and goes down onto the inboard side of the frame rail until it gets to the TC and then it goes into the frame rail to get to the back cross member. There are a couple of clips in front of each tail light on the top of the cross member to keep it in place. Along the way the reverse light switch and a couple of other wires (memory let me down here) come off the harness.

I know the '40s have a different back half so this may or may not be correct for your truck.
getting ready to completely re-wire our stock Feb 79' 40 series after a frame-up resto. Haven't found a wiring harness for this production date. What are you two using (motiv8r, 1979 FJ40ish)? Dad has some pics of evrything before he took it apart so I will see where ours was routed.
@Rainman, may have some inside to the issues you are dealing with.
I have a 2/79 FJ40 that is waiting to be restored. Wiring for the most part is still intact. From 1/79-7/80 I see no changes. Only thing I see is two versions of the main cowl harnesses for the US. One is listed as artic which I'm wondering if that was suppose to be A/C. My 79 had some kind of non operating aftermarket A/C when I bought. But is not a A/C model. When I stripped a wiring harness from a 1980 model that was in a salvage don't remember it having A/C in. That was probably twenty years ago but think if had a factory A/C would have at least tried to buy it. I was lucky this salvage didn't allow full harnesses to be pulled but was a regular customer they let back and pull the complete harness. IH8 aftermarket wiring.
I searched off and on for two plus years while my restoration was underway and, in the end, couldn’t find a wiring kit that I thought I could make work. If you study the OEM harness, you’ll see several dozen connections, required for various components, that you won’t find in any kit.

At first glance, my 79’s wiring harness looked bad but once I got the old tape and wire wrap off it the wires and insulation were in remarkably good shape. I cleaned and inspected the wires and had to replace several of the connectors that had cracked or broke over time but most of the actual repairs that needed to be made were because of damage done by previous owners.

Wherever I needed to splice in new wire I tried to match the original wire color coding, all connections were soldered and protected with heat shrink. I then replaced all the wire wrap and tried to replicate the way the harness had been factory taped, including the yellow tape used in several places.

The best thing is that every device and light worked correctly the first time I applied power to the cruiser.

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