how to identify model of alternator

[Milt]

My label is partially missing, but the alternator is a 105 amp model from mid 1990's. I had a terrible voltage spike while charging and currently have it at an alternator shop to inspect the stator (spelling?) and considering replacing all the diodes. I suppose alternator replacement would be considered as well, but not sure what to look for until the old alternator is identified for mounting purposes. I have it installed on a 27 hp Yanmar 3gm30f diesel. thx -- Alan

[Coulomb]

The replacement would be the 4023-S for the Yanmar engine.

If you're lucky, a local alternator repair shop will use the high temperature parts necessary.

[Milt]

OK, I can just make out the "1023" model number, shown as a 105/120 amp output ... If I figure out how to post a pic to this forum I will so so! In the meantime, my local shop (he repairs mostly starters and alternators from cars and tractors, not the high out put style like this alternator) feels the stator (spelling?) is bad due to its COLOR -- that being black, even though all the wires test as OK and the stator wire does not test as grounded. He felt the black stator wire shown it had been overheated, even though to me it looks mostly to be a black enamel paint coating! The diodes are another problem in that his supplier shows them as a Delco number, but his supplier cannot supply them! Are their sources for the diodes to purchase for rebuilds? The diodes are: (negative) MR5010R 9045, MR5010R 9045, MR5010R 9045 and (positive) MR5010 9043, MR5010 9044, MR5010 9044 ( a total of 6 diodes).

[Milt]

I am attaching pics of my alternator

[Milt]

the stator

[Milt]

the diodes

[Milt]

the front case

[Coulomb]

That's a 1023, replaced by the 4023. It has a 2 inch mounting foot.

[Milt]

I see rebuild kits available for the 4023 ... parts no longer available for the 1023? (like diodes!)

[Coulomb]

Parts in the 4023 kit will also fit, (and upgrade) the 1023.