W126 alternator ?

[BMJR]

Recently when driving my 88 300 SEL the battery light would light up very dim at idle RPM. I suspected the battery, so I checked and tested it. No problem with the battery.
Next I checked the current from the alternator to see if it was charging. It was putting out around 45 amps and keeping the voltage above 12 at the battery. So I figured everything might be OK.
Well about a week after that the red battery light would come on from time to time more constantly. However sometimes you could shut it down, start it back up and the light would go out.
Driving back home one night the battery light got brighter and brighter. I also noticed the headlights going very dim. Then the ABS light came on. I knew I had trouble then When the ABS light came on I touched the brakes and the radio which was on went off. let off the brakes and the radio came back on. Next the SRS light came on and the radio died completely. I drove another mile or so and the voltage level droped so low that it would not run anymore. Coasted a couple miles (downhill) to a nice spot to pull over. Keep in mind that I still have the lights on which are getting dimmer and dimmer. When I got stoped I turned everything off, and spent 10 minutes or so going over all the fuses, etc.
Knowing that it wouldn't crank I got back in and cranked it up. I couldn't believe it. It turned over very slow, but it did crank. I had my amp meter with me so I checked, and the alternator was putting out 50+- amps. The indicator lamps were all back to normal and everything seemed to be fine. I went home with no more problems.
The next morning I started it and checked the voltage and amperage. This time the light was back on again, battery voltage was slowly falling, and the alternator was only putting out 2 amps or so.
So that seems to indicate the alternator as the culprit. Although I can't understand why it would be an intermittent problem.
I think I'm going to pull the alternator tommorow and try rebuilding it. What do you think, guys.??
I hope it's not something else in the electrical system that is causing the alternator not to put out.