Alternator Question

[Bill B.]

65 327/300 coupe.

I have been doing research on alternators due to problems with my 68 Chevelle SS. I got those problems resolved and was looking at the one on my 65 Corvette tonight for comparison. I replaced the alternator several years ago at a Napa outlet.

The stamp casing is marked 1102480, 61 amp. with a date of 5A22. I googled it and found it was for a 75-77 application on several GM cars including Corvette. It is supposed to be a 10SI, however the rear of the alternator is set up for the 10DN plug instead of the spade type connector at the top of the alternator. Are rebuilt alternators purchased at parts stores a mix and match of cases or am I missing something. The system is working fine and I am having no problems but I am just curious. Thanks for any input to help me understand.

Bill B.

[Edward J.]

Re: Alternator Question

Bill, some of the Reman. companys do a internal by-pass to work with the external regulator and install a rubber plug where the internal reg. is suppose to go.

[Frank D.]

Re: Alternator Question

That is a case of the rebuilder repurposing an alternator for a specific application.

However, you will absolutely find mismatched bits and pieces on alternators that have been rebuilt. Just recently on here there was a thread that showed several '63 alternators that had '64 rear case halves instead of the one-year-only (and proper) '63 rear case....

[Bill B.]

Re: Alternator Question

I have the original wiring harness for a DN10 that was supposed to be for a 37 amp alternator so does that mean the internal parts are putting out 37 amps or 61 amps as the case has stamped? 61 amps instead of 37 doesn't concern me and it might even be better if I added something. Just curious and trying to expand my knowledge.

[Domenic T.]

Re: Alternator Question

Bill,
it will put out 61A.

Dom

[Domenic T.]

Re: Alternator Question

Bill,
I changed the internal parts of my 37 A and put 61 A internals in it. The case says 37 but the output is 61 A with the changed parts. The voltage regulator is OK with that also.

Dom

[Bill B.]

Re: Alternator Question

So, when an alternator gets rebuilt whatever is stamped on the case is what it is rebuilt to as far as amperage goes and what you're getting when you tell the parts counter person you need a alternator for a 65 Corvette. When I replaced that alternator several years ago I didn't have the knowledge that I do now and I didn't specify a 37 amp alternator, I just said for a 65 Corvette and took what he handed me. In this case it's no big deal but it could be and just shows me I need to do more research when replacing parts on my Corvette and chevelle.

[Bill B.]

Re: Alternator Question

Alternator 1.jpgAlternator 2.jpg I thought I'd go ahead and send pictures of the alternator in question incase anyone had anymore comments. Thanks for the comments.......Bill B.

[Joe L.]

Re: Alternator Question

[ATTACH=CONFIG]67738[/ATTACH][ATTACH=CONFIG]67739[/ATTACH] I thought I'd go ahead and send pictures of the alternator in question incase anyone had anymore comments. Thanks for the comments.......Bill B.

Bill-------


Large commercial rebuilders usually tear down alternators to their component parts. Many of the parts are cleaned and reused (e.g. cases). Some parts are rebuilt or repaired (e.g. rotors, stators) and some parts are discarded (e.g. bearings, brushes). All of the various aforementioned parts and some new parts are then used to build up alternators. In this process, the alternators are essentially built up the same way that Delco-Remy originally built up the new alternators.

The stamped numbers on the alternator cases mean absolutely nothing after an alternator has been through a commercial rebuilding operation. In fact, I've notcied lately that some rebuilders either grind off the numbers or cover them with a foil label. I suppose this is done to avoid just the sort of confusion that you describe.

By the way, a drive end frame from an SI series alternator can be combined with a DN series slip ring end frame to make up a DN series alternator. An SI series slip ring frame cannot be used to make up a DN series alternator. In other words, the drive end frames from SI and DN series alternators can be used interchangeably; the slip ring end frames cannot be used interchangeably.

[Domenic T.]

Re: Alternator Question

Bill-------


Large commercial rebuilders usually tear down alternators to their component parts. Many of the parts are cleaned and reused (e.g. cases). Some parts are rebuilt or repaired (e.g. rotors, stators) and some parts are discarded (e.g. bearings, brushes). All of the various aforementioned parts and some new parts are then used to build up alternators. In this process, the alternators are essentially built up the same way that Delco-Remy originally built up the new alternators.

The stamped numbers on the alternator cases mean absolutely nothing after an alternator has been through a commercial rebuilding operation. In fact, I've notcied lately that some rebuilders either grind off the numbers or cover them with a foil label. I suppose this is done to avoid just the sort of confusion that you describe.

By the way, a drive end frame from an SI series alternator can be combined with a DN series slip ring end frame to make up a DN series alternator. An SI series slip ring frame cannot be used to make up a DN series alternator. In other words, the drive end frames from SI and DN series alternators can be used interchangeably; the slip ring end frames cannot be used interchangeably.

Joe, can you define the SI,DN, for us that are not acronym talented?

Dom

[Joe L.]

Re: Alternator Question

Joe, can you define the SI,DN, for us that are not acronym talented?

Dom

Dom------


"SI" is the description that GM/Delco used for internal regulator type alternators.

"DN" is the description that GM/Delco used for external regulator type alternators.

I don't know that these 2 character descriptors are abbreviations for anything but they may be.

As far as Corvettes go, all 1962-68 alternators were "DN" and of series 10. The series relates to the physical size of the alternator and its components. Series 10 alternators range in output from 37 to 61 amps.

All 1969-82 Corvettes used "SI" alternators. From 1969 to 1976 all were series 10 with output of 42 to 61 amps. After 1976, some were series 12 or 15 with outputs from 63 to 70 amps.

By the way, Corvettes were among the very first GM cars to receive the "SI" alternators, first appearing for the 1969 model year. Only a few other 1969 model year GM cars got SI alternators. One that I recall was 1969 Pontiac GTO with rear window defogger.

[Bill B.]

Re: Alternator Question

I googled the DN and SI terms last night.. SI is abbreviation for System Integrated which is an alternator with internal voltage regulation. DN is abbreviation for Delcotron which was simply the original alternator with external voltage regulator and as far as I can tell has no other meaning. I hope this is correct.

I really appreciate the feedback.

Bill B

[Joe L.]

Re: Alternator Question

By the way, here are some photos of a GM #1100854 SI series alternator [not for sale] that was once installed on a 1969 Pontiac GTO with rear window defogger. This one is dated "9B11" (February 11, 1969). Does this configuration look familiar to you 1969 Corvette guys?

DSCN3233.jpgDSCN3234.jpgDSCN3235.jpg

[Domenic T.]

Re: Alternator Question

Joe, and Bill,
Thanks for that.

Dom

[Terry M.]

Re: Alternator Question

By the way, here are some photos of a GM #1100854 SI series alternator [not for sale] that was once installed on a 1969 Pontiac GTO with rear window defogger. This one is dated "9B11" (February 11, 1969). Does this configuration look familiar to you 1969 Corvette guys?

[ATTACH=CONFIG]67771[/ATTACH][ATTACH=CONFIG]67772[/ATTACH][ATTACH=CONFIG]67773[/ATTACH]

Very nice piece Joe. You are a font of wisdom.

BTW: There were some very unique internal features to the early 884 alternators. Maybe some day we will get around to judging those details.