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Alternator & Regulator: Description

There are 2 types of alternators used, the 12SI and 17SI (Systems Integral) series with built-in voltage regulator. All 12SI alternators have "Y" stator windings, while all 17SI have delta windings. See Fig 1. The CS130 (Charging System) alternators have a high amperage output. This alternator does not have a diode trio.

Fig 1: Alternator Terminal Identification & Locations
G71048Courtesy of GENERAL MOTORS CORP.