The Stovebolt Site Forums The Shop Area The Electrical Bay Alternator I. D.

Bought a rebuilt alternator at the Iola swap meet 2 years ago. Now I find that there are one wire alternators, 2 wire alternators, internally regulated alternators, externally regulators alternators and on and on. So how do I find out which one I have? This one has a big red terminal marked batt on the back and it looks like maybe a 3 terminal vertical female receptacle on the back also or it may be just some sort of a vent. On the lower back of the case it says Delco Remy. Anybody know what I got here? If I knew how to post a pic in a thread I would. Weeds

Weeds,

There is a neat page that shows ID clues for these alternators...someone will probably post it. The most basic points for ID'ing this are the orientation and location of the terminals for the DA plug.

If the terminals are on the back of the case, noted as R and F and are positioned this way II, it is a older unit that requires an external voltage regulator, which would be mounted on the firewall.

My guess is that it's at least a 10SI unit. This would have the DA plug located around the circumference of the case and the tabs, marked 1 & 2 would appear this way --.

Both styles will have a large BATT terminal. It isn't quite as confusing as you make it out to be. It's either a externally regulated type...older technology and more scarce than the SI, or internally regulated type.

The SI style can use three wires...or one wire. This would be obvious because the hole where the DA plug goes would have no terminals protruding.

My bet is that there is a Delco number stamped on the case that would give all the hairy details on your swap meet find.

Take a look at this link.
http://www.madelectrical.com/electricaltech/delcoremy.shtml

And maybe this link.
http://www.rowand.net/Shop/Tech/GmAlternatorIdentification.htm



Stuart

Stuart, thanks for the links. They will help me identify my orphan. Weeds

Stuart, using your link I think this is a 10SI. I still have a couple of questions. This was a fresh rebuild. Is it possible to convert an externally regulated alternator to a one wire internally regulator alternator? It looks like thats what happened to this one.

Weeds

Weeds,

I'm not quite sure on the question. A SI alternator IS internally regulated...either three wire or one wire.

The older "Delcotron" 1D series were the externally regulated alternators. I don't think they can be converted to a internal style regulator...the small solid state regulator won't fit properly inside the older case.

The Delcotron and the SI alternators look considerably different...are you sure you're looking at the correct picture?

Stuart

Stuart, this alternator has only one big terminal and it is marked BAT. There is a plastic plug riveted in the position on the circumference where I believe another electrical plug could be inserted. This plastic plug is permanent and I can't remove it which led me to believe that maybe it was converted from a 3 wire to a 1 wire. I will take a pic and attempt to post a link so you can see what I am babbling about. Weeds

Weeds, Most often on one wire 10si internally regulated self exciting delco alternators there is a black block out plug that is plugged into the case, this actually plugs into the two prongs on the internal regulator that has been converted to a self exciting regulator. When this is done you will only have one wire to hook up and that is from the large Bat. terminal with what should be a red insulator on it. This wire will make a path back to the battery...could take several routes depending on how it was wired up. If using an amp guage it will run through the guage and then back to the + on the battery, this may be accomplished by going direct to the battery or to the starter switch. If no guage is used, volt or amp, then it could go direct from back of alt. to starter switch or bat. If it is a self exciting alt. then once you get it hooked up you may have to rev up the rpms to excite the reg.
Let me know if I can help.
Ken
www.classicgenerator.com

Stuart and Kennethw here is a pic of the alternator.

http://picasaweb.google.com/rpweeden/49Sub/photo#5143255992684132050

You have a Delco Remy, 10SI, internally regulated, Self Exciting, one wire alternator. It excites off of RPMs and not electrically.
Ken
www.classicgenerator.com

Weeds,

Ken figured it out. They make plastic caps that snap over the DA plug hole when the alternator is equipped with a voltage regulator capable of one wire service...I have never heard of one being riveted on though.

Your alternator will "self excite"...electrically, it just takes a quick pop of the throttle. This is what Ken meant I'm sure.

While dinking around on a Delco parts site, lo and behold, I found a add-on deal to make a 10DN alternator into a "faux SI" unit. It's a little solid state regulator with a couple of pigtails hanging out of it.


So my previous statement that the old external kind can't be converted was incorrect...not the first time.

The picture you linked shows a brand new rebuilt, nice looking unit all setup for single wire service. Good luck.

Stuart

Stuart, you are correct, there is a small external regulator that mounts onto one of the 10DN thru bolts. I have done this several times. Its just a maybe one inch long solid state reg. so to speak with wires comming out of it. It works really well.
Ken

Stuart and Ken, Thanks for helping me figure out my alternator, the people on this site are the greatest for getting questions answered. What would I do without my Stovebolt? Weeds

Stu and Ken, thanks for the help.

Weeds

take your alt to an auto ele shop they can tell you what you have and how to install..doc