Cheap Alternator Upgrade?

[85 Cutlass Brougham]

I am thinking I need to do a alternator upgrade, but I also want it to be cheap, and junkyard sourced. It has to be a V belt alternator, preferably a 10si or 12si. The problem I noticed is that I can watch the voltage gauge reading go down in proportion to where I set the volume on my stereo, and goes up when I turn down the volume. It has a moderate amount of wattage (about 800 max), but I am concerned that I will be killing batteries and alternators if I am not careful. Is there a good junkyard solution to my dilemma? What cars should I look for to find a decent sized alternator, like say maybe a 100+ amp model? The Pontiac Parissienne wagon taxi alternator that is in there right now I am afraid won't cut it for too long.

 

[joe_padavano]

I am thinking I need to do a alternator upgrade, but I also want it to be cheap, and junkyard sourced.

My kind of upgrade! 😀

The 1990s B-body cars with the transverse Series II 3800 V6 have a nice CS130 with the mounting lugs in the 12:00/6:00 positions, making it a bolt-on replacement for the 10SI/12SI alternators. These all came with serpentine belts, but you simply need to swap the pulley from your old alternator and it works fine. You can get a conversion harness if you don't want to deal with the wiring issues, or cut and paste the connector if you don't want to spend the money. My friend just installed a junkyard CS130 on his 64 Grand Prix and is very happy with it ($15 at the local yard). The CS130s came in 85A and 105A versions, so check the stamping on the case when you get one.

 

[Longroof79]

Good information, Joe. Thanks for that. One question. Do you need a different type of mounting bracket for the CS130, or is it a direct bolt on?
I know that it requires a different plug/ wiring harness.

I'm currently using the garden variety 10si unit that needs to be replaced with something that has more output. I would like to run electric fans and be able to use A/C again.

Jack

 

[nycutlass]

I am thinking I need to do a alternator upgrade, but I also want it to be cheap, and junkyard sourced. It has to be a V belt alternator, preferably a 10si or 12si. The problem I noticed is that I can watch the voltage gauge reading go down in proportion to where I set the volume on my stereo, and goes up when I turn down the volume. It has a moderate amount of wattage (about 800 max), but I am concerned that I will be killing batteries and alternators if I am not careful. Is there a good junkyard solution to my dilemma? What cars should I look for to find a decent sized alternator, like say maybe a 100+ amp model? The Pontiac Parissienne wagon taxi alternator that is in there right now I am afraid won't cut it for too long.

just use a cs 130 its 105 amps at idle and you will be set just keep in mind that at lower rpms it will be higher amps than it would be at higher rpms its not like a 10si or 12 si that the faster the rpms the more it charges.oh and this setup will not charge your batt unless its almost at full charge to start with !!!if you need more details let me know i can hook you up with a wireing plan for 1 wire if needed.i been running this setup now for years ,with no problems