If you do not know which alternator came with your Fiero, check the Option Codes sticker on the left front fender well next to the spare tire. Then look up your alternator type on the Option Codes page of this web site.
We do not recommend installing an unknown used alternator except as a matter of expediency. With today's improved electronics we suggest you get the alternator rebuilt by a professional rebuilder using an upgraded diode set. (Remanufactured alternators from parts suppliers are typically built to minimize cost, not optimize quality.) We have had 145 amp diode sets installed in two Fiero alternators at a cost of $75 each. Results have been very satisfactory.
Repairing an alternator can be done at home if you are handy. "How To" procedures are prolific on the Web; a Google search will reveal dozens of good tutorials and we have a good article on alternators in the Tech Articles section of this site. The most frequent alternator failure is the "diode trio". Rockauto.com Sells the diode trio for under $4. The part is #D11, Standard brand.
'84-87 66 Amp: This alternator was used in both 2.5L and 2.8L engines. The cars listed below had other alternator choices besides the 66 amp, so an exact match is not guaranteed. Alternators of higher capacity can be used in place of the 66 amp if they fit.
Pontiac 2000 '83-84 1.8L Pontiac Pontiac 6000 '83 2.5L Pontiac 6000 '83 2.8L VIN "X" (8th digit) Pontiac 6000 '83 4.3L Pontiac 6000 '84 2.5L Pontiac 6000 '84 2.8L VIN "X" (8th digit) Pontiac 6000 '85 2.5L Pontiac 6000 '85 2.8L Pontiac 6000 '85 4.3L Diesel Pontiac 6000 '86 2.5L Pontiac 6000 '86 2.8L Chevy Blazer S10/GM Jimmy S15 '86 2.0L Chevy Blazer S10/GM Jimmy S15 '86 2.8L Blazer/GM Jimmy (full size) '83-86 Buick '83 Camaro '83-86 Cavalier '85-86 2.5L Chevy Celebrity '83-86 Buick Century '83-86 Chevy Forward Control '83 Chevy Forward Control '84 Gasoline or Diesel Chevy Forward Control '85 Diesel Chevy Forward Control '85-86 Gasoline Chevy Forward Control '87-90 Gasoline Chevy Passenger '83 Chevy Passenger '84-85 Gasoline Chevy Pickup Truck '83 Chevy Pickup Truck '84 Diesel Chevy Pickup Truck '84-86 Gasoline Chevy Pickup Truck '87-88 Gasoline Chevy Van '83 Chevy Van '84 Gasoline or Diesel Chevy Van '85 Diesel Chevy Van '85-86 Gasoline Chevy Van '87-90 Gasoline Olds Ciera '83-85 Olds Ciera '86 2.5L Olds Ciera '86 2.8L Chevy Citation '83-85 Olds Cutlass '83 Diesel, 8 cyl. w/o tach Olds Cutlass '83 Gasoline Firebird '83-86 Olds Firenza '83-86 1.8L Olds Firenza '85-86 2.8L GMC Forward Control '83 GMC Forward Control '84 Gasoline or Diesel GMC Forward Control '85 Diesel GMC Forward Control '85-86 Gasoline GMC Forward Control '87-90 Gasoline GMC Pickup Truck '83 GMC Pickup Truck '84 Diesel GMC Pickup Truck '84-86 Gasoline GMC Pickup Truck '87-88 Gasoline GMC Van '83 GMC Van '84 Gasoline or Diesel GMC Van '85 Diesel GMC Van '85-86 Gasoline GMC Van '87-90 Gasoline Pontiac Grand Prix '83 Chevy Malibu '83 5.7L Diesel Chevy Malibu '85-87 Chevy Monte Carlo '83 5.7L Diesel Chevy Monte Carlo '85-87 Olds '83 Olds '84 3.8L Olds Omega '83-84 Pontiac Phoenix '83-84 Pontiac '83 Pontiac '84-85 Pontiac '86 Olds Regal '83 Except 6 cyl. diesel Olds Regal '86-87 5.0L S10/S15/GM Sonoma '83-84 2.0L S10/S15/GM Sonoma '83-85 2.8L S10/S15/GM Sonoma '84 2.2L Diesel S10/S15/GM Sonoma '83 2.0L Diesel w/o tach Buick Skyhawk '83-86 1.8L Chevy Sprint (GMC) '83 Chevy Sprint (GMC) '85-87 Chevy Suburban '83 Chevy Suburban '84 Diesel Chevy Suburban '84-86 Gasoline Chevy Suburban '87-88 Gasoline Pontiac Sunbird '85-88 1.8L
'84-87 94 Amp: This alternator was used in both 2.5L and 2.8L engines. The cars listed below had other alternator choices besides the 94 amp, so an exact match is not guaranteed. Alternators of higher capacity can be used in place of the 94 amp if they fit.
Pontiac 2000 '84 1.8L Pontiac 6000 '84 2.5L Pontiac 6000 '84 2.8L VIN "X" (8th digit) Pontiac 6000 '84 4.3L Except California Pontiac 6000 '85 2.5L Pontiac 6000 '85 2.8L VIN "X" (8th digit) Pontiac 6000 '85 2.5L Pontiac 6000 '85 2.8L Pontiac 6000 '85 4.3L Diesel w/o tach Pontiac 6000 '86 2.5L Pontiac 6000 '86 2.8L Pontiac Astro '85 Chevy Blazer S10/GM Jimmy S15 '84 1.9L Blazer/GM Jimmy (full size) '87-88 Gasoline Buick '84-85 3.8L Buick '84 5.0L w/o Air Conditioner Olds Calais '85 Camaro '83-86 Cavalier '85-86 Chevy Celebrity '83-86 Gasoline Buick Century '84 Diesel, except California Buick Century '84-86 Gasoline Chevy Forward Control '86 Gasoline Chevy Forward Control '87-90 Chevy Passenger '85-88 Gasoline Chevy Pickup Truck '85-90 Gasoline Chevy Van '87-90 Olds Ciera '84 Except California Olds Ciera '85 Gasoline Olds Ciera '86 2.8L Cadillac Cimarron '85-86 Chevy Citation '85 Olds Cutlass '87 5.0L Firebird '83-86 Olds Firenza '85-86 2.8L GMC Forward Control '86 Gasoline GMC Forward Control '87-90 GMC Passenger '85-88 Gasoline GMC Pickup Truck '85-90 Gasoline GMC Van '87-90 Pontiac Grand Am '85 Pontiac Grand Prix '84-87 Chevy Malibu '85-87 Chevy Monte Carlo '85-88 Pontiac Phoenix '84 Pontiac '84-85 Gasoline Pontiac '86 Olds Regal '84-85 Gasoline Olds Regal '86-87 5.0L Olds Riviera '84-85 6 cylinder S10/S15/GM Sonoma '84-85 1.9L Pontiac Safari (GMC) '85 Buick Skyhawk '84-86 1.8L Buick Skylark '84-85 Buick Somerset '85 Chevy Sprint (GMC) '85-87 Chevy Suburban '85 Gasoline Chevy Suburban '87-90 Pontiac Sunbird '85-86 1.8L
'87 85 Amp: This alternator was used in both 2.5L and 2.8L engines in 1987 but is unique to the Fiero. If the alternator needs to be replaced, use the 94 amp (above), get the original rebuilt, or obtain one from a donor Fiero. The 85 amp and 100 amp alternators from the '88 Fiero will fit the '87.
'88 2.5L 85 Amp: This alternator is unique to the Fiero. If the alternator needs to be replaced, use the 94 amp (above), get the original rebuilt, or obtain one from a donor '87-88 Fiero. The 100 amp alternator from the '88 Fiero will fit.
'88 2.5L 100 Amp: This alternator is unique to the '88 2.5L Fiero. If the alternator needs to be replaced, rebuild the original or get one from a donor '88 2.5L Fiero.
'88 2.8L 85 Amp: This alternator is unique to the '88 2.8L Fiero. If the alternator needs to be replaced, rebuild the original or get one from a donor '88 2.8L Fiero. The 100 amp alternator from the '88 2.8L will fit.
'88 2.8L 100 Amp: This alternator is unique to the '88 2.8L Fiero. If the alternator needs to be replaced, rebuild the original or get one from a donor '88 2.8L Fiero.