I was looking online for a alternator to replace the weak one I have. Does anyone know what the case style of the stock alternator is?

The site has alternators with these styles
10si
12si
cs121
10dn
cs130

 

Do you need the alternator upgraded...or just repaired? If the one you have is original and you want to keep it, just look up a "Starter and Alternator Repair" shop and have them do it. Or, if you are a DIY guy, just buy the diode sets, capacitor and brush kit from them (or NAPA) and dig in. It's only about a 1-2 hour job.

P.S. The little drilled holes in the back plate are for sticking straightened paper clips into so they can hold the 'new' brushes in place while you assemble it all. Then remove them. Simple... And, no, you don't have to pull the fan off the front, unless you need to change the bearing, too.

 

A "Starter & Alternator rebuilder" Can rebuild your starter with a higher capacity, usually. Look for one in your area in the yellow pages, you might be surprised at how cheaply you can have this sort of work done.


Scott

 

10si

 

Had my chrome alternator rebuild locally for $60. Might be cheaper where you live or DIY.

Otherwise pay $100+ for another chrome one

 

My 81' needs more than the stock... I am running the correct alternator for an 87', just took the alternator to NAPA and said that i needed an alternator for an 87, then swapped the pulleys right there in the store. 10 or so years now with no problems... not chrome though

 

The stock alternators are more than powerful enough to get the job done. What's wrong with yours?

 

I had my original alternator rebuilt at a local starter/alternator rebuild shop for $35. Found out that it was not charging the battery properly and have not had any trouble (especially starting while hot) ever since.

 

Thanks everyone for the input.

As far as the above adding an amp and a few other goodies along with many years of service it is giving up the ghost. If I have to replace it might as well go bigger. Electric fans in the future.

The rebuild maybe an option I will look around here.

 

I had mine done at a local shop, brought it up to 130 amps (I'm running dual elec fans) for $90.

 

If you do not need extra capacity just have the OEM one rebuilt or rebuild it yourself if you are handy-it is really very easy if you have some basic skills. As for upgrading a stock alternator 10si housing to higher amperage, I would not recommend that route based on the following:

1. I bought a new 10SI 120 amp alternator to replace my 63 amp alternator and it worked fine and still does BUT high amperage alternators in a 10/12 SI alternator body will generally NOT charge well at idle under load (gen light would flash)-I know from experience and hearing from alternator experts.
2. Using a high amperage stator, diodes, and brushes in a 10/12SI body will run very HOT under high load and will result in premature alternator failure rates.
3. you are MUCH better off upgrading to the more modern GM alternators like I did-a 140 amp CS144 with much better cooling and amperage capacity. See the link below:

http://store.alternatorparts.com/del...lternator.aspx

 

After doing some checking I went with a proform 120 amp. I seems to cover all I need.

 

What wiring changes are necessary when switching from original type to CS144?

 

Well, a high output alternator trying to push more current through the 45 year-old existing [and smaller] wiring does not bode well for the fusible links in the system. One might think about what current is being drawn and where to upgrade wiring and fuses as necessary.

 

What I ment was: is it a plug and play kind of a swap or is there some changes with the wires or plug at the alt end?

EDIT: found some discussion which could be relevant to my question but it seems people are having some trouble in finding the correct pigtail to do this: SI to CS144 conversion

 

I switched my 120 amp 10Si to the CSI 144 140 amp alternator listed above from National Quick Start in the link I posted previously and the alternator bolted right into my 78 using all the original brackets and even the OEM belt. Call them and they will send you the correct "clock" position alternator with the correct fan. The only extra item you need is the pig tail adapter wire that hooks into the alternator from the OEM connector-no cutting involved-the link was $17. There are 2 types of adapter wires-one for cars without gen lights and one for ones that do have a gen light. IT IS REALLY VERY EASY! Call them and they will give you exactly what you need.

As for the comments about the OEM wiring not a heavy enough gauge for high amp alternators, my answer is that it depends on what exactly your amperage requirements will be. In my case, the OEM 63 amp alternator is marginal for a car with A/C and other OEM options but it can do the job IF I did not have Euro Hella Halogens that draw at least 25 amps with the high beams on. At most, I draw about 80-90 amps with everything on! Can the stock wiring handle that additonal load?-absolutley and it has for 25 years! The reason for my higher amp alternator is that a 63 amp alternator can't do the job. Could an 80-100 amp alternator handle that load? Probably but it would work really hard, generating tremendous heat which can kill the alternator, especially at idle. the CS144 140 amp alternator is barely sweating that load and can easily handle it at idle. That is the reason for the higher amperage 140 amp alternator. If the alternator needed to provide 140 constant amperage, THEN I would agree that a wire upgrade is needed but for most applications the stock wiring is just fine. Hope that helps!

 

Thanks for the info!

I too run Hella halogens and plan to install electric fans and will install an EFI system so i wan't to be prepared for all that.

I have lost 5 or so CS130's due overheating in my C4 and then converted to CS144 which has lasted fine. I think I even still have a tech tip posted on how to do that conversion to a C4.

But I haven't upgraded a C3 alt so all tips are welcome.

 

The CS144 alternator is a much better alternator than the CS130-Mostly the advantage is around the housing of the CS144 and its cooling abilities which are much better than the CS130! Sounds like heat was killing the CS130's which is the point i was making about upgrading 10/12SI alternators to high amperage-They will work for a while but the heat generated will kill the alternators. Hope that helps!

 

Yes, rectifiers and also bearings fry in CS130's. I even upgraded one of my CS130 to "Iceberg"-configuration with better ventilated case and more durable parts it but also failed soon. So, CS144 is the one I trust.

 

jbL78-82...

So, if the poster does the alt upgrade without upgrading any wiring, and then runs his battery down pretty well playing the stereo without running the engine to keep the charge up, then starts the car...with a battery that screams "SEND ME MORE JUICE!!" to the alternator, and it does...and then fries the fusible link [or worse, burns up the wiring]...

Are you going to fix the damage?

To the OP:

Rotten advice from this responder. But, it's your car. Do....or don't do....whatever you want.