The Snakes Alive CMP Wiring Project

[Jacques Reed]

Good Day,

I’ve decided to re-do my 25 year old wiring harnesses on my F15-A.

A number of reasons:
Basically back in the mid-nineties I copied non-original harnesses that were on my first truck. At that time I did not even have a Repair Manual for a wiring diagram so I copied the colours and wire gauges as best as I could estimate from the existing harnesses. A bad call in hindsight.

Interestingly, those harnesses I copied used plastic covered wires but they were in original looking woven cotton shrouds. I am surprised they weren’t cotton braid covered wires, but perhaps someone went to a lot of trouble to run wires through the original shrouds even if wrong colours were used.

Another consideration was adding turn signal wires. I know it isn’t original but I believe it is essential in modern traffic to have them. The wires are less obvious inside the new original style harnesses. I made them slightly longer to differentiate them from the original wiring and give a bit more clearance at the solenoid.

I also wanted to add the Autopulse wire to the harnesses. Although not used on Australian vehicles it could come in handy to add an electric fuel pump, if required, at a later date. The wire was fitted originally even if not used but I left it off my first version.

I had hoped to use cotton braid covered wire but I opted for modern automotive wire instead. In reality, very little of the wire is visible so I couldn’t justify the high cost of a commercially made harness. I would not be able to reproduce the woven cotton shrouds anyway so it made even more sense to go with modern wire. I used vintage style bitumen impregnated conduit for the shrouds instead which, although not original, looks in keeping with the era of the truck. I spent about $175 for all the materials.

I obtained a rough, but complete, main harness a while back and a NOS horn (lower chassis) harness for patterns. Over time, I have measured all the lengths of wire and tabulated what I needed in colours and wire gauge.
I used Tycab Australian made automotive wire throughout. I tried to use trace wires wherever possible to identify the wires similar to the original colour coding. In some cases the wire/trace colour combinations were just not available however. In those cases I added a length of heat shrink tubing of the appropriate trace colour to identify it.

I made one exception to the original colour codes. I made the horn wire from the solenoid orange/green band to avoid confusion with the left fuel sender. Both are normally yellow/green x 2. Only a few inches of the horn wire at the solenoid is visible so I can live with that.

So the instrument panel is done, the horn harness is done, so just the main harness to finish off. All wires for it have been cut and run so a just bit of soldering to finish it off.

Hope this is of some interest.