Reference Manual

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Chapter 5: Electrical: 140-amp Alternator upgrade

Article by: Jon Hennecke

Lets face it, the stock alternator is pretty weak on our G-bodies if we are using aftermarket stereos, electric cooling fans or any other power hungry accessories. I swapped in a 140-amp alternator from a 1994 Pontiac Transport (3.8L w/rear a/c)¹. It went pretty easily. I just had to make a trip to the GM parts dealer to pick up a special harness. It allows you to plug in the stock alternator plug in the harness then into the newer alternator (part number # 12083462) It's a self-explanatory install:

• Disconnect the battery
• Remove stock alternator
• Install the new alternator
• Install the adapter harness
• Plug the factory harness into adapter
• Plug the adapter harness into alternator
• Reconnect the battery

¹Additional alternator info: GM part number 10463338, AC-Delco part number 321-594. Used for the applications below. -Ed.

• 1994-1996 Buick Roadmaster Limited V8 5.7L 350 cid Engine Vin = P
• 1994-1995 Buick Roadmaster Estate V8 5.7L 350 cid Engine Vin = P
• 1996 Buick Roadmaster Limited Wagon V8 5.7L 350 cid Engine Vin = P
• 1994-1996 Buick Roadmaster V8 5.7L 350 cid Engine Vin = P
• 1994-1996 Cadillac Fleetwood Brougham V8 5.7L 350 cid Engine Vin = P
• 1994-1996 Cadillac Fleetwood V8 5.7L 350 cid Engine Vin = P
• 1993 Cadillac Fleetwood Brougham V8 5.7L 350 cid Engine Vin = 7
• 1993 Cadillac Fleetwood V8 5.7L 350 cid Engine Vin = 7
• 1993 Chevrolet Caprice V8 5.7L 350 cid Engine Vin = 7
• 1994 Chevrolet Caprice V8 5.7L 350 cid Engine Vin = P
• 1994 Chevrolet Caprice LS V8 5.7L 350 cid Engine Vin = P
• 1993 Chevrolet Caprice Classic V6 4.3L 262 cid Engine Vin = Z
• 1994-1996 Chevrolet Caprice Classic V8 4.3L 265 cid Engine Vin = W
• 1993 Chevrolet Caprice Classic V8 5.0L 305 cid Engine Vin = E
• 1994-1996 Chevrolet Caprice Classic V8 5.7L 350 cid Engine Vin = P
• 1993 Chevrolet Caprice Classic V8 5.7L 350 cid Engine Vin = 7
• 1994 Chevrolet Caprice Classic LS V8 4.3L 265 cid Engine Vin = W
• 1993 Chevrolet Caprice Classic LS V8 5.0L 305 cid Engine Vin = E
• 1993 Chevrolet Caprice Classic Ltz V8 5.7L 350 cid Engine Vin = 7
• 1994-1996 Chevrolet Impala SS V8 5.7L 350 cid Engine Vin = P
• 1992-1995 Chevrolet Lumina Apv V6 3.8L 231 cid Engine Vin = L
• 1992-1995 Oldsmobile Silhouette V6 3.8L 231 cid Engine Vin = L
• 1992-1995 Pontiac Trans Sport V6 3.8L 231 cid Engine Vin = L

NOTE: This swap may require swapping a serpentine pulley on the sourced alternator with your original pulley!