How to Identify Alternator and Need for Regulator

[Fleetwood Meadow]

I bought a 1952 Cadillac engine in December. It came with a 6 volt pertronix ignition and alternator. I am getting ready to wire the alternator in and I don’t know what I am dealing with. The casing has no name or model markings on it. I have not gotten the engine to idle long enough to see what it is putting out for voltage. I see the battery terminal and a spot where a plug was. It says R and F (1 and 2). Does this indicate that it is externally regulated? Is there a way to tell what this alternator is and if I need an external regulator? If it does need a regulator is the generator regulator acceptable to use or do I need a specific alternator regulator?

 

Edited June 15 by Fleetwood Meadow
Added pictures (see edit history)

[Lee H]

Search “10SI alternator” and you’ll come up with all the info you need. This one probably has a 6v regulator built in.

[Bloo]

That's internally regulated. If it were for an external regulator, the spade lugs would be rotated 90 degrees. As built, one of those spade connections is for the idiot light (opposite side of bulb is connected to the key switch), and the other spade is a battery voltage "sense" wire that GM often neglected to use.

 

If the alternator has been converted to 6v, then the internal regulator, which is the piece with the two spade lugs on it, is not a GM part. Any information about how to hook up the aftermarket regulator would have to come from whoever made it. It is possible that it is a "one wire" version and you don't have to hook anything up.

 

[Frank DuVal]

If it is a three wire alternator, the F terminal goes to "hot" and the R terminal goes to the dash lamp and then the ignition switch (to tell the alternator to turn on when the key is turned on).

 

If it is a one wire alternator then you will have no indication of alternator failure unless you put a voltmeter on the dash.🤬

 

Does it say if it is negative or positive ground alternator? Same with Pertronix. Hate to see you weld those solid state parts inside either if the polarity is connected wrong.😮

[Bloo]

The positive ground conversions of alternators like this typically have a kludge with a hole in the back where they brought out the opposite end of the diode pack, and have the original output post strapped to ground. Maybe they aren't all that way? In any event, I believe Cadillac abandoned Positive Ground long before 1952.

 

Did this car ever run and drive with the parts in question? I would wonder less about polarity, and more whether it is really a 6 volt alternator (unless you already saw it working as a 6 volt alternator in the past).

[JACK M]

Something else about the one wire alternators.

They don't get excited until it gets a good goose.

[TerryB]

3 hours ago, JACK M said:

Something else about the one wire alternators.

They don't get excited until it gets a good goose.

Me too some mornings….

[Oldtech]

The above advice is all good.  The " most likely" scenario , looking at it, is that it is an ordinary 12 volt SI alternator, in which case all that you need is the connection to the BATT. terminal. About a no. 10 wire, and switched power to the terminal 2 (F).  The  terminal numbered 1 is most often used for a charge light. 

[Frank DuVal]

But, the 1952 Cadillac is a 6 volt system.......😮

[JACK M]

12 hours ago, Frank DuVal said:

But, the 1952 Cadillac is a 6 volt system.......😮

A six volt one wire alternator is not uncommon.

pos and neg grounds are available.

[TTR]

I realize OP asked only about ID’n the alternator and potential need for regulator, but was it made clear what kind of application this engine and/or its charging system components are intended for ?

 

A ‘52 Cadillac, ‘87 Buick, 29 Duesenberg, ‘07 Dodge Truck, airplane, boat or oil well pump with 6V or 12V with negative or positive ground system?

 

Or is it just that nobody cares about basics like this before offering answers or opinions which may or may not be accurate or applicable without them ?

 

 

 

Just curious.

Edited June 17 by TTR (see edit history)

[Fleetwood Meadow]

I was pretty clear in my original post that it was on a 1952 Cadillac. I stated that it was 6 volts. Since Cadillac used 6 volt negative ground in 1952 I neglected to mention the polarity. But I gave a basic level of information then I just watched the random guesses coming in. I got enough information for what I was looking for with some of the responses. I’m going to start the engine and see what it puts out. 

[Lee H]

Remember, you get what you pay for.

[Frank DuVal]

I knew it was a '52 Cadillac and 6 volt, just unsure of ground polarity. I answered accordingly.

 

Lee, I have gotten much more than I paid for in deals and also not as much as I paid for sometimes when I buy things at a fair price. One is never sure until the dust settles!