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Guys;

I've got a question regarding voltage regulation. I have a 1962 M37 with a 230 CI flathead industrial engine installed in place of the original engine. I bought the truck this way. Now, this engine does not have the normal looking setup of a generator and voltage regulator mounted on the firewall. In fact the generator itself appears to be different as well. My concern is that since I see no voltage regulator, has someone simply rigged this truck to run without a voltage regulator. If this is the case, then I am in danger of the batteries exploding correct?

Now, I have heard of internally regulated generators/ and alternators, and am thinking (hoping)maybe this is the case with my truck. Unfortunately I don't have a photo of my setup, or I'd include it here. I'll try to explain it as best I can. My generator is identical to a 60 amp alternator listed in MVM magazine. I'm using the term "generator" because it says "60 amp generating system" on the ID tag on the unit. The unit does not have that large cable running to it with the 90 degree elbow which attaches just back of the pulley, but rather it has two or possibly three wires soldered to the back of the unit on top in a spot that has posts that appear to look as though wires were meant to go there. I know this doesn't say much but thats the only way I can describe it. This wiring setup connects via a coupling to the main harness and I assume then somehow feeds the batteries etc.

Is there a way I can tell if I am getting voltage regulation from this unit by checking voltage to the batteries while the truck is idling or revving etc? I have heard that a certain voltage to the batteries is normal under charging conditions but what I don't know is what do I look for to clue me in that something might be wrong. I hope I am explaining things right. Anyway any info you could provide will be appreciated.

Hello NICKATHOME, And while I'm the first to respond to your query, I am probably the least knowlegeble, but here goes: Yes, You can check for the presence of voltage regulation by measuring the voltage at the batteries. I recommend starting with thee engine off. Measure the volts. Then start the engine, and watch for a difference in volts. Then you can turn on the lights, and see what effect it has on your voltage. Do you have a working ampmeter? Does it respond when you work the lights? Spend a few monents watching your volt meter and if you see increases and decreases in voltage value it indicates regulation. Oh yes, and crank your engine for a while to bring the battyry volts down, and then watch to see the volts climb as the gen or alt recharges. On my civilian cars I notice recharge volts of 14.4 VOLTS. Hope this helps. peter mark

Hi, thanks for your response. What I am most concerned with is a runaway of voltage to the batteries as I rev the engine as through driving. I'm most concerned with that tna anything else.

I forgot to ask you what your battery voltage is? I have 12 volts presently ( for which I am on John Bizals BLACKLIST ) I would imagine that if you had no regulation, your batterys would have blown up by now ! Peter

Hi Nick,
From your description your alternator/generator sounds like an old GM unit. I have one from a mid-80's GM truck on my M and the regulator is an internal type with two options for hooking it up: a two-prong plug slot, and also a single-wire post, both on the back of the unit. Those attachments are the actual end connectors to the internal regulator. Mine too, is 12V.
Gary

Cal_Gary wrote:Hi Nick,
From your description your alternator/generator sounds like an old GM unit. I have one from a mid-80's GM truck on my M and the regulator is an internal type with two options for hooking it up: a two-prong plug slot, and also a single-wire post, both on the back of the unit. Those attachments are the actual end connectors to the internal regulator. Mine too, is 12V.
Gary

I have a 24 volt system. From what I recall I have a military generator/alternator. The engine itself even though industrial, has a milspec number on its ID tag as well.

peter e mark wrote:I forgot to ask you what your battery voltage is? I have 12 volts presently ( for which I am on John Bizals BLACKLIST ) I would imagine that if you had no regulation, your batterys would have blown up by now ! Peter

Peter;

I have also had the same thoughts! But just want to be sure

Nick,
Without knowing what you have (a photo or a posting of the numbers on the dataplate of the generator or alternator would be nice...): You likely have a unit that was "upgraded" with one of the alternators off a M151 or M35 that is a 60amp 24 volt internally regulated unit. Actual adjustment process is the same for each in general, but slightly different in practice as the units aren't identicle from manufacturer to manufacturer and from one decade to the next...

If you have been running the truck and haven't cooked your batteries yet, you either aren't charging at all or aren't overcharging (or you just haven't run it much...)...

Put a voltmeter on it when the engine is running and tell us what your output voltage is... Should be 28volts for a 24volt system...

Good luck.

From what you describe it's a 60 amp alternator (generating system in milspeak), these have an internal regulator, nsn NSN should be on the tag and read 2920-00-909-2483! Should only be 2 wires large wire is the charging, small is the sense.

Ken;

Thanks for the national stock number, I will check it. I wasn't sure of how many wires connect to it but 2 seems about right. I'll have to take a look today.