[elkper1771]

My alternator is shot, anyone know what amp. alt. it should take? Got an '87 V-8, 305 w/ AC and A.T. Someone let me know & Thanks - George :???:

 

[BillyJack]

I believe the OEM alternator was 78 amps. There were many different units used on GM cars of that era that were all interchangeable. The one I have in my '87 currently is a 94 amp.

Bill

 

[elkper1771]

The orig. engine?

Hi BillyJack, Is that the original engine for a 94amp? I have the OEM V-8 and the Alt. shows no clue of the amp. requirement. - George :???:

 

[Bobby78]

George
The specs for 78 call for a 61 amp when optional A/C is ordered. But most rebuilts are higher now anyway. Talk to the parts guy and see what he has close to 100 amp with the same body, not the bigger ones.
Another option is to go to the local rebuilder and have him rebuild yours with higher output. This might be cheaper since you cut out the middle man.

 

[elkper1771]

Good idea,..

Hey Bobby,
Specs are 61amps? But even a better idea is to get it rebuilt. I do know that the internal voltage regulator is shot. Hey,.. Thanks Buddy ! - George :smileyb:

George
The specs for 78 call for a 61 amp when optional A/C is ordered. But most rebuilts are higher now anyway. Talk to the parts guy and see what he has close to 100 amp with the same body, not the bigger ones.
Another option is to go to the local rebuilder and have him rebuild yours with higher output. This might be cheaper since you cut out the middle man.

 

[Bobby78]

Yeah George hard to believe in 78 the base alternator without A/C was 37 amps!
Makes you hope it never rains at night when you need defroster, wipers, headlights, and signals!

 

[BillyJack]

Hi BillyJack, Is that the original engine for a 94amp? I have the OEM V-8 and the Alt. shows no clue of the amp. requirement. - George :???:

OEM GM units have the amp rating stamped into the case. once they get rebuilt, that stamping becomes irrelevant, since you don't know what pieces are inside. I wasn't happy with my original unit, so I acquired one from a similar year Monte Carlo with a 4.3 V6 and it was 94 amp.

Bill

 

[Beepster]

You will also need added amps if you happen to have an electric fan(s). THEY drink juice like an alcoholic!!!!!!oke:

 

[BOOSTED-SS-ELKY]

63 amps is what a stock 10/12si puts out. Why did your alternator go bad? Is the battery good? Have it charged and load tested before you replace the alternator. A bad battery will smoke an alternator fast. If you have added any electrical accessories to your car, don't put a stock alternator back on it. I'd get a 90 or 100 amp.