The Snakes Alive CMP Wiring Project

[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

[Jacques Reed]

Good Day,

With another year closing I thought it was time to finish off another loose end. I wanted to rewire the wire tails on the various lights on my F15-A. All of them had hard brittle insulation and the light base contacts on some were in poor shape.

Backtracking a bit: A year ago I had a local gasket manufacturing company make me some 15mm diameter fibre washers to replace the base contacts on those lights. Interestingly they did not stamp them out but used a high pressure water jet to cut them.

My originals had a small eyelet in the middle into which the wire was soldered. I note some light bases used a rivet on the wire end instead, but all mine had eyelets.

I obtained some brass eyelets online and installed them in the disks after drilling the holes for them. The material was too tough to use a punch and anyway I wanted to make the holes as accurately as possible on centre.

I made up a jig to hold the wire and base contact for soldering using a piece of wood. I drilled a 5/8" diameter 2mm deep recess with a wood spade bit then followed through on the drill press with a 4mm diameter hole. This made a nice firm fit to hold the wire and located the contact right in the center. I filed a groove in a soldering iron tip to make contact with the wire and rounded the back to contact the eyelet. Didn't show it here, but I used masking tape to hold it down in the jig during soldering.

With a couple practice runs it was a simple job to get a perfectly soldered contact. In fact, looking at my originals I am much closer on center than the originals in some cases. Two things to remember however: tin the wire end first and do not hold the soldering iron tip to the eyelet and wire for more than about 5-10 seconds. My first attempt heated the wire too much and made the plastic insulation swell which made it hard to remove from the jig and one to be scrapped.

Hope this is of some interest and a Merry Christmas to all.

Cheers,

[Jacques Reed]

Good Day All,

Tidied up another loose end- no pun intended, with the cowl wiring for an Australian CMP two headlight cowl.

Finished the small harness from the terminal block to the dip switch thanks to Keith Webb's diagram. Noticed a hole in the splash guard which just begged having a clip there to keep the harness from rubbing on the clutch pedal arm.
Checking two other splash shields all three had an identical hole at the same place so obviously it had some purpose. I will take a punt that it was for a clip for the harness to keep it off the clutch arm.
Without a sample of that harness, I took an educated guess at the wire lengths. Possibly longer than original but they can be shortened if good info comes to hand.

I also fabricated the harness from the terminal block to the lights. I used a very rough original as the pattern which gave me accurate wire lengths. I also added turn signal wires to it with bullet connectors for easy removal should I ever want to remove them.

Although not 100% original it is as close as possible as I could make it. I used fork terminals or ring terminals where required and attached them to the terminal block in the same manner as shown in Keith's diagram. Covered the ring and fork terminals with silicon rubber self-vulcanizing tape.

Original harnesses were covered in a braided sleeve at manufacture but I used bitumen-impregnated cotton loom. Slightly bigger diameter than original harness to accommodate the two extra turn signal wires.

The lower two original unused terminals were just right for the turn signals.

Hope this is of some interest.

Cheers.