Need advice on 12V conversion alternator

[meck]

When I bought my 640 fifteen years ago, it had already been converted to 12V with a one wire alternator. Now, the alternator is making a squealing sound, and it sounds like its coming from the bearing when I listen to it with a stethoscope. I can't find anything on the alternator to identify what it is, so can anyone tell me what I need to buy to replace it. Online, I see all kinds of one-wire alternators advertised and discussion/arguments about them. I would rather get a recommendation from some of you all with experience. I appreciate it.

 

[MeanGene1]

The ones sold on this site work very well, and their claim that they will start charging at low RPM is valid. I got kits from here for my 8N and my 450, brackets, pulleys and belts all good

 

[Eman85]

Most likely a GM alternator, pic would help. Easy to disassemble and replace the bearings and every other required part. The internal regulator is what makes it a 1 wire alternator. A 3 wire will work and would only require 1 extra wire with a diode from the ignition circuit to work and they are available at every parts store.

 

[sotxbill]

A delco 10si will work, or a "one wire" will work. Look up the cheapest "1976 chevy c10 remanufactored alternator" if your tight on money.

I see new ones on Amazon for $63.99 and with my Amazon prime acct, I get free shipping( and streaming to Prime Video...) both are a big win for me.

 

[old]

When I bought my 640 fifteen years ago, it had already been converted to 12V with a one wire alternator. Now, the alternator is making a squealing sound, and it sounds like its coming from the bearing when I listen to it with a stethoscope. I can't find anything on the alternator to identify what it is, so can anyone tell me what I need to buy to replace it. Online, I see all kinds of one-wire alternators advertised and discussion/arguments about them. I would rather get a recommendation from some of you all with experience. I appreciate it.

The one wire alternators are modified Delco 10SI alternators and Delco didn't make them that way. Most auto parts store carry them but they cost 3 times more then the common 10SI

 

[sotxbill]

The one wire alternators are modified Delco 10SI alternators and Delco didn't make them that way. Most auto parts store carry them but they cost 3 times more then the common 10SI

Rumor was... that the one wire's were made for inboard boating applications, dont know if thats true or not. And that pretty much all 10si alternators today have a bleed resistor added so that they self excite.. but you have to rev them up a little to get them to "trip" into service. Where a true one wire will excite at an idle?? Truth? or Dare? I just buy the "rebuilt 10si's" and in some cases, you get a new one anyway. Be careful as some "rebuilt alts" require a "core" and some dont. Thats a 40 buck charge if you dont have a core.

 

[MeanGene1]

Rumor was... that the one wire's were made for inboard boating applications, dont know if thats true or not. And that pretty much all 10si alternators today have a bleed resistor added so that they self excite.. but you have to rev them up a little to get them to "trip" into service. Where a true one wire will excite at an idle?? Truth? or Dare? I just buy the "rebuilt 10si's" and in some cases, you get a new one anyway. Be careful as some "rebuilt alts" require a "core" and some dont. Thats a 40 buck charge if you dont have a core.

The ones sold on this site will charge at just off idle, as claimed. I have used two of the kits on an 8N and an 850, they have the proper pulley and belt and good fitting brackets, and the price isn't bad with no core charge

 

[meck]

Thank you all for your information and advice. It looks like there are several options, but after considering them all, I bit the bullet and ordered one from this site.

 

[Eman85]

Take a few minutes and take your old alt. apart and see how it works and what's bad. You should mark the case halves so you clock it back the way it was. The only trick is pushing the brushes back and retaining them with a paper clip wire while reassembling.