The Snakes Alive CMP Wiring Project

[Jacques Reed]

Hi Keith,

A great find and will it be very helpful! Answers a few wire gauge size questions too. Many thanks for posting it. I noticed the remains of fork type terminals on mine too. Guess this makes for easier disconnection if one wants to remove the cowl and not lose terminal screws.

Cheers

[Jacques Reed]

Hi Keith et al,

That diagram was a great help. Attached is a wiring diagram I made which may be of use to fellow restorers. Between your diagram, the remnant of a dip switch with a bit of the harness left, and the remnant of the cowl harness and terminal blocks I think it is all correct but, as always, glad to hear from anyone if there is an error.

There are some wires not listed in the Parts Manual wiring diagram but on your diagram due to the two headlight configuration: namely 1a, 2a, and 4a

The wire gauge sizes are off your diagram and match the remnants I have found. The lengths are the wire lengths as measured off the cowl harness from bullet to terminal. The lengths of the dip switch harness wires are my best estimates and may require adjustment.

The turn signal wires are purely for my benefit to agree with the Falk turn signals I have installed.

Cheers,

[John Winfield]

Finished my rewiring job a week or two ago (well, almost – no high beam indicator circuit). In the end, gave up trying to duplicate the existing wiring, since it was in such rough shape, and just pulled it all out and rewired to the manual. I even went so far as to create a quick 3D model on CAD to get a guess at wire lengths (that's the brake circuit showing).

I've also added a couple of before and after shots:

It's still a little rat's nesty behind the dash, but maybe I'll get back in there some day to clean it up (but probably only if I have problems). Some other wires are a little long, so I may trim them back at some later date.

I made a few changes from the manual. I put in two regular tail lights. There's no sign of the small tail lights on my CMP, or the switch at the back for the differential light, so I didn't bother with them. I also wired up the switches so the side lights are on their own switch, without it lighting the tail lights, or the head lights lighting the side lights. Probably shouldn't have bothered with the brake isolation switch either, since I'll probably hit it accidentally a few times. I set up the inspection light socket, but didn't actually hook it up – don't think I really want a live socket up there.

I did buy a few little harnesses from MAC's. I got headlight harnesses, a cross harness for the tail lights, a Mercury harness for the instrument lights, and I also got a cowl light repair set to do the side lights. Unfortunately they are sold out of the high beam indicator harness, with no word of when they'll be back in stock.

The lights all seem to work as advertised (once I put in a new brake switch). The engine turns over and the horn works, but I haven't started it since the rewire for other reasons.

I bought my wire from Rhode Island Wiring – they seemed to have the biggest selection of colours. Also, most of the connectors. I crimped the ends, on the advice of a friend who does wiring on helicopters. He showed me a fancy crimper that crimps from four sides at one time, and serendipitously happened on a much cheaper version at an estate sale the following Saturday, when I went over to Buffalo NY to buy some 6 volt sealed beam headlights.

I'm a lot more comfortable now, having gotten rid of that old wiring.

John

[Jordan Baker]

Does anyone know if the Wireless CMP trucks had fully shielded wiring harnesses similar to what’s in my picture?

[gjamo]

I have 3 NOS wiring looms that I bought years back. Two I think are Chev and 1 is Ford.The switches are cruder than I have seen on my blitz so may assumption is that they are early, possibly cab 11/12. Does anyone recognize them?

[Ganmain Tony]

Fairly confident they are Ford 12/11 Cab Graeme

[Hanno Spoelstra]

Originally Posted by gjamo

I have 3 NOS wiring looms that I bought years back. Two I think are Chev and 1 is Ford.The switches are cruder than I have seen on my blitz so may assumption is that they are early, possibly cab 11/12. Does anyone recognize them?

Can't read the part number, but they look like these posted on page 1 of this thread:

Originally Posted by Hanno Spoelstra

“WIRING HARNESS. Thought to be for the early style cab, 11 & 12 Ford. Never used. 4 switches, 3 light sockets. Metal identification tag C11Q-14401C.“

C11Q-14401C is the latest version of "Wiring - cowl" for the Cab 11 and 12 - ref. http://www.mapleleafup.net/forums/sh...334#post222334

[David Dunlop]

Jordan.

For most of the wartime production, that shielded harness was the type used for all Wireless Vehicles, all weight classes. Two identical harnesses were in production: the standard cloth loomed ones used on none wireless vehicles, and the metal shielded looms for wireless as you have shown.

At some point late in the war, I do not know when, the practice of producing two separate wiring harnesses stopped and only one was produced thereafter. This final version was essentially a shielded harness like you posted, but with an extra overlay added, the outer jacket is some sort of fibre/cloth impregnated with a black, tar like substance.

I have been told that once the final version arrived, it was to be used as replacement harness in all vehicles. Perhaps it was felt that all transport would benefit by better electrical shielding and from that point on, only Wireless Vehicles had the extra ignition shielding added. It has also been suggested the extra jacket over the loom was a corrosion prevention asset.

In any event, you are OK with the shiny shielded harness on a CMP Wireless Vehicle.

David