Ignition Coil and Cable

[Rack Grade]

So....I have blown through 2 "Chromies" - These chrome canned ignition coils made in Taiwan. First one on my '54 M37 was on there when I got the truck last year and looked like it was going to burst. Second failed almost immediately. The top was pushing out and off and fluid was coming out. Pieces of junk.

New I am installing an NOS unit.

Problem is the darned main cable from the coil to the distributor cable is all buggered up and I need to replace it. Its not staying connected to the coil despite many efforts to MacGyver it. GRRRRRRRRRRRRRRRR!

I don't see this cable at VPW. Anyone know what the replacement is for this, which will attach correctly to the coil? Current one I have here, (and which I am only assuming is correct) says "7mm High Heat" on it.

[m37paul]

Call VPW, I think they have it. Midwest Military does, also. Are the vent lines hooked up? They help with coil cooling. Good luck.

[just me]

7mm? Coil to dist? I'm confused. There is no large 7mm HT cable inside a waterproof distributor. The wire from the dist input to the coil is maybe 14ga with a spade connector. The other from the breaker plate to the coil.

[Elwood]

Sounds like someone moved the coil outside of the waterproof housing, and ran a regular automotive type coil wire from the coil to the cap? Mine was butchered that way when I bought it.

In an original setup, the cap connects to the center output of the coil by an extension molded into the cap, and a spring on the underside of the extension, with the spring fitting down into the terminal in the center of the coil tower. There is no wire connection between the two.

Here's what a similar Auto-Lite distributor looks like in cross section. The "Connector Spring" is the physical and electrical connection between the distributor cap and the coil.



With the cover (which includes the cap affixed to the inside) removed, your distributor (aka "ignitor") should look like this with the coil installed:

[NAM VET]

Here are two pictures of the military waterproof distributor when I removed it as part of my rebuild. I then put in new points and such, and hopefully it will give me a good spark when I reinstall it.


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[Rack Grade]

Great pics and thanks so much this clarified it for me.

Elwood is correct. Someone did a non military set up and the coil is mounted outside the distributor. I do not have the waterproof milspec distributor setup.

So..... a regular cable does not set I to the coil seat/hole and hold there. What previous owner did was insert booted wore i to the hole. Then zip tied the thing onto the coil sonit would hold in there.

Worked for awhile. Probably still would work, But i need a better solution I think

[just me]

A 24 volt civilian type coil is the answer.

[Carter]

A 24 volt civilian type coil is the answer.

I have several military 24V. NOS civilian style coils available, will post pix if you are interested.

[just me]

I too have 3 or 4 new civilian 24v coils in my collection. (They were used on some industrial stuff.)

[Carter]

A 24 volt civilian type coil is the answer.

I have several military 24V. NOS civilian style coils available, will post pix if you are interested.

PM sent.

[Rack Grade]

As a follow up:

I am told now that complete change back to waterproof distributor may entail new oil pump as well. Distributor shaft on the civilian one is centered. On the military waterproof its a bit offset. Said if wrong oil pump there would be a wobble in the operation of the distributor. Also I need to make sure I have ETW-1 so I can hook up vent lines.

So looks like restoration is plugs, cables, waterproof distributor, vent lines, maybe oil pump.

[Elwood]

As a follow up:

I am told now that complete change back to waterproof distributor may entail new oil pump as well. Distributor shaft on the civilian one is centered. On the military waterproof its a bit offset. Said if wrong oil pump there would be a wobble in the operation of the distributor. Also I need to make sure I have ETW-1 so I can hook up vent lines.

So looks like restoration is plugs, cables, waterproof distributor, vent lines, maybe oil pump.

If you have a civilian distributor and oil pump combination, you'll want to change the oil pump to the military style if you go with the military waterproof distributor. Even if you get the offset tang on the military distributor to engage with the centered slot on the civilian pump, the eccentric action will wear the plain bushings in the distributor, and eventually it won't be able to hold the correct point gap, etc.

NOS military oil pumps are available from the usual sources, at least one of which offers them for less than $100. Just be sure to check it over against the wear limits in the manual when you receive it; sometimes even the NOS ones are out of spec.

[Cal_Gary]

I blew a coil once by not using the ballast resistor-broke wide open with fluid spewing out.
Gary

[MSeriesRebuild]

A ballast resistor is not needed if you are using all the correct components.