Basic alternator question (wandering voltage)

[bowen1]

I just completed an upgrade to a 140 amp alternator. I went down to the local alternator starter shop and asked what would work in the factory location. We came up with an alternator out of a Cadillac. It has a slightly larger housing but it did fit. They put on the proper pulley. This alternator had a digital regulator in it, it puts out 14v all the time even at idle with everything on (full power accs). It is a one wire hook up and fairly easy to install. Hope this helps.
Bobby

 

[dyeager535]

An alternator upgrade may be in my future, if this rectifier doesn't change things, I won't have much choice but to get another alternator, and a lifetime warranty is pretty appealing. About $80 FWIW.

 

[dremu]

I just completed an upgrade to a 140 amp alternator. I went down to the local alternator starter shop and asked what would work in the factory location. We came up with an alternator out of a Cadillac. It has a slightly larger housing but it did fit. They put on the proper pulley. This alternator had a digital regulator in it, it puts out 14v all the time even at idle with everything on (full power accs). It is a one wire hook up and fairly easy to install. Hope this helps.
Bobby

I'd be interested in any identifiers you have for this -- part #, application, whatever. I'm assuming a much newer Caddy than our trucks, if we're talking about a fancy shmancy regulator?

-- A

 

[dyeager535]

And since this is my thread, I'll put this link in here:

http://store.alternatorparts.com/index.asp?PageAction=VIEWCATS&Category=903 lots of pictures and parts. Of course, anything with a GM number I found is about 1/2 the price on gmpartsdirect.com (like the rectifier bridge)

 

[dremu]

And since this is my thread, I'll put this link in here:

http://store.alternatorparts.com/index.asp?PageAction=VIEWCATS&Category=903 lots of pictures and parts. Of course, anything with a GM number I found is about 1/2 the price on gmpartsdirect.com (like the rectifier bridge)

What? I only slightly hijacked it =))

-- A

 

[bowen1]

I'd be interested in any identifiers you have for this -- part #, application, whatever. I'm assuming a much newer Caddy than our trucks, if we're talking about a fancy shmancy regulator?

-- A

I wish I could tell you the part number. This alternator shop is the old fashion kind, we compared housings and pin locations and came up with one.

I do know that I was able to use a one wire hook up where before there was also a plug. There is a place to plugin a plug but not used. The plug that it takes is the newer water proof type.

I think the cadys have a lot of amps needed to run everything thats why the 140 amp is used.

I will try to find out a part number for you.

Bobby

 

[dyeager535]

Just a general update, this thread is dead.

I decided to be methodical about this by swapping pieces one by one between the alternators, then testing on the truck. I didn't feel like testing components, which leaves a big problem, that the same problem could exist in both of course.

Anyways, got to the point where I had swapped out everything BUT the stator and rotor. Rectifier, brush holder, diode trio, regulator. All acted the same. Essentially as it warmed up, voltage dropped off, unable to compensate at idle for load. Down to 12 volts. RPM input brought alternator output up to 14V+.

Got to the point of swapping rotors, and found the rotor was stuck to the bearing in the front housing. Broke the housing trying to get it out. Given up on this since I no longer have the parts to continue "testing", decided to try a CS130 upgrade. Really just increasing how much work I have to do.