alternator amperage
 

The alternator in my car says:

1100 901 62A
9L 12v neg



It appears to have 10 gauge wires. stock size?

So I assume its 62 amp.


question is, how big of an electric rad fan, can I run without alternator upgrades?
electrically, the system is stock. the car does not have AC or a stereo or anything unusual.

I would not try to run an electric fan at all with a 62 amp alternator. Mine used to be a 63 amp and was just barely good enough to maintain my battery status and all I had originally as an option was a radio.
I upgraded to a 94 amp 12Si when I added EFI, fuel pump, and then I upgraded to a 140 amp CS-144 when I also added a/c and a Lincoln Mark 8 fan.
Within the last 2 years I had a problem with my CS-144 so I installed the 94 amp 12Si to see how it di.....it really does NOT do well at idle. It cannot maintain terminal voltage at idle; it does fine at higher RPM, but not at idle. I fixed my terminal connectors and reinstalled my 140 amp CS-144. It works wonderfully.

I would recommend going straight to a CS-144 since they're really relatively inexpensive now (mine cost me 20 bucks at a junkyard about a dozen years ago... I didn't know if it was any good, I just wanted to see if it fit).

i don’t know if all years are the same but my ‘70 has a 10g alternator wire with 2g battery cables.

I changed my alt wire to 8g and swapped battery cables to the later 1/0 gauge.

If wanting stock appearance, heavier double wound stator are available that will push a 10si up to 100 amps.

You won't be able to run an electric radiator fan to replace the mechanical fan successfully with that alternator. You might get away with running a smaller supplemental fan that draws much less current, but that would be all. You didn't really say what you were expecting the fan to do, but to replace the mechanical fan on a C3 requires a charging system upgrade.

There is no 10SI alternator that does particularly well at idle. It'd due to the fundamental design and why GM changed to completely new designs instead of upgrading the 10SI any further. So, I'd also recommend just going right to a CS130 or CS144 or a newer AD244 alternator. The AD244 fixes some of the shortcomings of the CS144.

I Have an alt. called a 17SI, 108 amp factory rating like off a '79? loaded Caddy.....larger diameter but mounts same.....have to change pulley, but no biggie....

been on my upgraded '72 for many years.....