Alternator Conversion

bigcol · Post by **bigcol** » Sun Jul 17, 2011 1:12 am

RE: 03/1951 M38.

Decided to replace the original generator/ regulator with a new 24 volt Delco alternator due to constant breakdown problems and rebuilds.

I'm now left with (1) the "male" regulator cable & connector and (2) the lead that I disconected from the starter. I placed a alligator clip from the battery onto the original remaining connector and located the individual power pin that's supplys power to ignition.

Q. what do I do with the remaining old starter cable I removed. Is this needed with the new conversion. I also don't really want to butcher the old cables & intend on returning to the original system when time & finances permit?

Appreciate any help.

Col (Melbourne Australia).

Post by **wesk** » Sun Jul 17, 2011 10:13 am

Are you using a true Delco one wire or are you using the 2 wire plug and the main power wire?

Is it a model 10SI?

bigcol · Post by **bigcol** » Mon Jul 18, 2011 5:02 am

Thanks for replying Wes.

It's the Delco 24 volt alternator Model 10SI 50AMP 1 wire hookup direct to battery.

Col

Post by **wesk** » Mon Jul 18, 2011 8:51 am

The simple approach if you want to leave a stock appearance and an easy restoration back to stock later is to just stow the plug by bagging it in a zip lock bad with a wire tie backup for the zip and then tie it to the regulator mount bracket.

Disconnect wires # 8, 9, 10 at the dash and zip lock bag them and zip tie the bag and tie them out of the way. Disconnect # 4 wire from the starter and tie it tightly to the harness.

Now run a new 10 or 12 gauge wire from the new alternator to the starter battery terminal. Then run a new 10 or 12 gauge wire from the starter battery terminal to the dash and connect it where you disconnected the # 10 wire. Another consideration you may have is to install a 50 amp circuit breaker or fuse in the new power feed.

The amp meter used a shunt in the old mechanical regulator which you no longer have installed so the amp meter will not function. You can use this type amp meter as a direct in series unit with your new power feed because it could never stand the raw load. The solution is to install the military volt meter in it's place. All you need to do is connect the new voltmeter positive terminal to wire group #27 spider so it is powered only when the main switch is on.

All of the above can be easily reversed if and when you decide to return to stock.

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Some options you can apply above would be:

Use the original alternator firewall harness and plug with the new alternator by leaving wire's # 4 & 10 connected as original. Bag and tie #8 & 9 as above. Slip a bit of heat shrink over pins B & D of the old regulator firewall plug. Then fabricate a short jumper wire of 10 or 12 gauge with two female pin sockets that fit the male pins in the plug and install the jumper on pins A & C. Then secure the covered plug carefully both to the jumper and the old regulator bracket. Now just run one new 10 or 12 gauge wire from the alternator to the starter battery terminal.

Or you could completely remove the plug and it's four wire harness by unwrapping the tape from the harness and sliding the 4 wires from the bundle. Then re-tape the remaining wires.

Here are a couple of wiring diagrams that show both ways. They are M38A1 diagrams but are essentially the same for our purposes.

There are a few more illustrations that may interest you on the last page of my photo album:
http://www.willysmjeeps.com/v2/modules. ... hp&page=17

kendak · Post by **kendak** » Mon Jul 18, 2011 9:04 pm

Wes; what M series vehicile would the replacement volt meter come in ?..I need to do the same thing in my M38 ....you can get a replacement genny for $200 or less but the reg. is $400 or more thats wild !!....thanks ...Kent

bigcol · Post by **bigcol** » Tue Jul 19, 2011 4:57 am

Thanks Wes. Will opt for the first "simple" option for time being. Many thanks.

Col

Post by **wesk** » Tue Jul 19, 2011 10:09 am

The late M170, M37B1, M151, and just about all the post 1955 M series trucks. Just go to Saturn Surplus or most of the Mil Surplus dealers and they will have them.