How to Identify GM Alternators
- 1). Examine the Delco-Remy alternator. The alternator is located at the front of the engine, usually toward the passenger's side of the block. Look for a fan with a pulley on the front, with a belt attached to the alternator and the main pulley at the front of the engine. On the back of the alternator housing, "Delco-Remy, Made in U.S.A" is cast in raised letters in a prominent location.
- 2). Locate the Delco-Remy identification tag or sticker. At the factory, Delco-Remy places an identification tag on the alternator housing. This tag contains the Delco-Remy model number, the AC Delco part number and alternator specifics, such as voltage and amperage. The ID tag contains the necessary information for proper identification of the Delco-Remy alternator.
- 3). Identify the differences between Delco-Remy and GM alternators. Differences between alternators with the same model number exist, mostly concerning the amount of power, or amperage, the alternator produces. Vehicles with many electrical devices and options require an alternator with a larger amperage rating. The amperage rating is found on the ID tag, and can be referenced by using the AC Delco part number. For example, the Delco part number "321-39" identifies a model 10SI with a 63 amp rating. Always use the AC Delco part number when referencing the alternator, or dealing with a parts or service department.