SI alternator in 72 cutlass
May 2nd, 2018, 06:53 PM
#1
Chris
Thread Starter
Join Date: Jul 2011
Location: Southern New Jersey
Posts: 1,285
SI alternator in 72 cutlass
hi! I know this thread was on here from severs years ago but I can't find it. If I decide to (and please tell me the pros and cons of doing this) how would I go about replacing my original alternator with external voltage regulator and a stock points/ condenser setup with a more modern SI internal regulator alternator? What and how would I reword? Is there any point to this?
thanks!
chris
thanks!
chris
May 3rd, 2018, 06:46 AM
#6
Old(s) Fart
Join Date: Mar 2007
Location: Northern VA
Posts: 47,663
Search for D9212S (the "S" is for solid state). It's a plug-in replacement for the mechanical regulator. About $25 from various on-line sources.
May 3rd, 2018, 11:52 AM
#7
Chris
Thread Starter
Join Date: Jul 2011
Location: Southern New Jersey
Posts: 1,285
Do you all think using a new solid state voltage regulator would be better than using a 35,000 mile original that I know works? I saw in an older post some concerns about the new Chinese built solid state regulators.
I appreciate your thoughts.
Chris
I appreciate your thoughts.
Chris
May 3rd, 2018, 12:11 PM
#8
Old(s) Fart
Join Date: Mar 2007
Location: Northern VA
Posts: 47,663
It was simply presented as an alternative to your question about swapping in a 12SI. If you have converted to an electronic ignition, the solid state regulator will provide "cleaner" power; the mechanical regulator can create voltage spikes when the contacts open and close that can take a toll on ignition modules. If you are happy with the current alternator and regulator, then carry on.
May 3rd, 2018, 12:34 PM
#9
Registered User
Join Date: Sep 2009
Location: Austin, TX
Posts: 331
hi! I know this thread was on here from severs years ago but I can't find it. If I decide to (and please tell me the pros and cons of doing this) how would I go about replacing my original alternator with external voltage regulator and a stock points/ condenser setup with a more modern SI internal regulator alternator? What and how would I reword? Is there any point to this?
thanks!
chris
thanks!
chris
Tim
May 3rd, 2018, 05:25 PM
#10
Chris
Thread Starter
Join Date: Jul 2011
Location: Southern New Jersey
Posts: 1,285
Ok. I understand. So if I take my si to get tested they will be able to determine how many amps? I understand that if it was rebuilt then the case may not be accurate as to its amperes.
Thank you
chris
Thank you
chris
May 3rd, 2018, 08:31 PM
#11
Registered User
Join Date: Sep 2009
Location: Austin, TX
Posts: 331
Tim
May 3rd, 2018, 08:36 PM
#12
Out of Line, Everytime😉
Join Date: Dec 2006
Location: Melville, Saskatchewan
Posts: 9,004
Try and find a GM 12si 94 amp alternator. I find the 10si chrome alternators all fail eventually. The only one that lasted anytime probably put out more like 70 or 80 amps. My current 94 amp 12si Wilson reman on my 88 CSC needs revved to start charging. I do like my 70 amp Chrome Summit 10 DN external regulator. The performance tag said 52 amps at idle and 81 amps at cruise. It has kept up no problem, even when I ran electric cooling fans.
May 5th, 2018, 02:27 PM
#13
Registered User
Join Date: May 2018
Posts: 7
10si
The stock regulator in your 10SI, if it's a GM reg., is much better then aftermarkets. If it's still good go with it. I used to rebuild alternators for years, old Chrysler, big pain, but I've seen very few GM regulators fail. Most fail due to diodes. Especially cheap diodes. Hope this helps.
May 5th, 2018, 03:34 PM
#14
Registered User
Join Date: May 2018
Posts: 7
On that 12SI. You should not have to rev it to get it to charge. It's losing it charge in the rotor. Try taking a small screw driver.At the rear housing, if I haven't forgot, should have a D hole. Take the small screw driver a stick in the hole and ground it to the rear housing for just a moment. That will excite the circuit and it will keep the charge in the rotor. One way to check if it's charged up is put the screw driver, on any piece of metal, to the rear housing bearing and see if it's magnetized. If it is, your alternator is ready to be used and you should not have to get to high rpm's for it to turn on. I hope this helps and it should solve your problem. If it doesn't then you have a leak somewhere in the alternator.
Last edited by Tootalu; May 5th, 2018 at 03:36 PM.
December 22nd, 2021, 07:08 PM
#17
Old(s) Fart
Join Date: Mar 2007
Location: Northern VA
Posts: 47,663
First, this is a thread about a 1972 Cutlass, and second, it's about converting to a 12SI alternator, which has an internal regulator. What exactly are you asking? If you want to convert to a 12SI, you don't want an external regulator. Maybe you should start your own thread and give us the details about your particular car.
Thread
Thread Starter
Forum
Replies
Last Post
442mark
Parts For Sale
7
September 30th, 2017 01:06 PM
yeahbuddy
Parts Wanted
4
March 6th, 2012 04:22 AM
Kaline
Parts For Sale
0
March 22nd, 2008 08:31 PM
