M38a1 generator not producing voltage

[randog]

I have a 1952 M38A1 that is 12v, the generator is not generating any voltage, how do I rebuild, and where can I get the parts?

Thanks[/img]

[wesk]

Rebuilding antique generators and starters is getting tougher every year. The few remaining available parts are quickly bought up by overhaul shops. Often special tooling & test equipment needed for proper overhauling is not available to the general public or too expensive.

The most common Group 3 12 volt GDJ series generators utilize 25 pages in the TM 9-1825B just for the overhaul of them so I quick or short lesson here is not feasable.

Next I must ask how you determined the 12V generator and not it's regulator was at fault? Did you test the generator by full fielding it or motoring it over?

Finally I must ask that if you are not trying to keep the M38A1 stock 24 volt why throw additional funds at a 50 year old system that can be replaced for $100 with a one wire modern alternator in the 60 to 100 Amp output range?

[randog]

would all I need is a alternator or is there more?

[wesk]

You'll need the alternator, a pulley to match the engine, and a adapter mount bracket. There are two common brackets available. Since your harness is already modified for the 12 volt generator you can use those wires if they are of sufficient gauge. Preferably 10 or 12 gauge for the Armature wire and 14 or 16 gauge from the field wire which would then be used to signal the alternator when the engine was operating. Wiring depends on the alternator you choose but I suggest staying with a Delco one wire which can be wired using only the large armature wire but I prefer adding the sense wire attached to the ignition switch.

There are several web sites with details on the switch and several suppliers.

http://cj3b.info/Alternator.html

http://www.novak-adapt.com/knowledge/12_volt.htm


This is one bracket.


This is the other

[randog]

could you tell me the delco one wire part number please

Thanks

[wesk]

Most Delco 10SI and 12SI series alternators can be converted to true one wire ops. There are several to choose from. I search by model number IE Delco 10SI 100A

Here is one result:
http://www.jegs.com/i/Powermaster/713/37127/10002/-1

Here is the one wire conversion kit:
http://www.jegs.com/i/JEGS-Performance- ... 0/10002/-1

Here'a a site that goes intop detaiul on one wire conversion:
http://mightymo.org/Proj_OneWire.html