I'm Going All Coolerman

[45Kevin]

On the way back from Cruiserfest last fall my tail lights stopped working. Just the running lights, brakes and signals still work fine. The front running lights work fine as well.

So I finally dug into it a bit today.

It looks like the white/black wire has melted. It probably fused into the green wire for the rear running lights. No fuses have blown though.

What I want to do is make a new harness that runs from the two plugs on the firewall and goes back to the tail lights.
I have a wiring diagram in my FSM for a '79 40. It looks like the wire colours are the same.

Can anyone tell me what the gauges of the wire is.
It looks like some wires are different gauge from the others.

And is the harness just wrapped in regular electrical tape, or is there some kind of ninja style wrapping involved.
I'll reuse the existing connectors.

 

[73fj]

I think the tape is regular black tape from what I can tell on three different Cruisers I have owned, wrapped with care by mama-sans from the factory.

 

[cult45]

I think the tape is regular black tape from what I can tell on three different Cruisers I have owned, wrapped with care by mama-sans from the factory.

I concur. But if all else fails get a harness from the coolerman himself and tho at sumbitch in ayer! I had my truck fully rewired and I now drive with no fear of fire

 

[45Kevin]

Thanks guys.
Coolerman told me the factory gauge is 18 but he used 16.
I'll get me some rolls of 16 ga.

 

[Michael B]

X2 on Coolerman!

 

[45Kevin]

Well, Coolerman hooked me up with the wire and connectors I need.

I am well into the job now and have run into a snag.
The fuel sender connection has three wires coming from it. See second pic.
According to my FJ40 wiring diagram from the FSM, the yellow/red goes along the harness to the firewall and on to the gauge, the black/white goes to ground and there is no mention of a green wire, which on my old harness goes up the harness to the firewall. I will mention that I have '78 FJ45 with the tank under the seat. The wiring diagram is for a '79.

The black/white splits and goes both ways. Going towards the back it splits again several times and going frontward it goes about a foot and stops. No termination, just cut and buried in the harness.

Can anyone shed some light on this weird condition.

 

[45Kevin]

The factory connectors at the firewall and at the tail lights are in very good shape and have a rubber grommet where the wires enter the connector to make it waterproof. I will clean them up and reuse them. The original parts label was still on the old harness, so I cleaned it up and taped it onto the new harness I am making.

I got a good start tonight, until I ran into the snag with the white/black wire from the fuel gauge sender connection.

 

[Michael B]

Mark has the 78' wiring diagram.

 

[45Kevin]

The more I stared at the old harness, and the wiring diagram, and the birth of the new harness, the clearer things became.
There were several places that some of the wires split. The factory harness had a 1/4" of the insulation stripped off, and used a little crimp to connect the split.
I didn't have any little crimp thingies, so I soldered the split, then I slipped a piece of heat shrink over the split.

There were a number of places along the run that had an added piece of protection for the harness. Just a piece of split tube that was wrapped around the wires under the tape. I wasn't sure if they were for protection, or to stiffen the harness. I reused them to do both jobs. I put the split tube under the tape wrap in a few places to give the harness stiffness at the off shots to the marker lights and used it as
protection where the clips kept the harness tight to the frame.

 

[45Kevin]

Mark sent me a roll of tape to wrap the harness. It wasn't your normal electrical tape, it was a kind of Saran Wrap type of tape with no adhesive. I advanced the wrap about 1/8" each turn, The total length of the harness was about 17 feet. That's a lot of wraps.

Here is the finished version, before it gets installed.
I left off the rear connectors.
The tail light connectors would not fit through the small gap between the pick-up box and the frame so i installed those after I had run the harness through that gap.
The marker lights and license plate lights, well I don't have those so I just coiled them up and taped them in the coil out of the way.

 

[45Kevin]

And... SUCCESS

I did have a slight problem.
For some reason, I messed up the tail light and the brake light on the DS. I fixed it by reversing their wire positions in the connector. Maybe I got the wire positions mixed up when I recorded them as I took them apart.

Anyway, I'm good for another 38 years at least: and I'm looking for side marker lights and a license plate hanger and light.

 

[ceylonfj40nut]

I know this is an old thread. How much wire (length) and how colors did you need? About to do the same.

 

[45Kevin]

I know this is an old thread. How much wire (length) and how colors did you need? About to do the same.

I don't remember.
I'm not even sure I measured what he sent me.
I just told @Coolerman what truck I had and what I wanted to do and he hooked me up with all I needed.
It was very reasonably priced, probably no more than I would pay for the materials at my local auto parts place, and everything was included.