Last night while driving home, the headlights would occasionally dim a little bit, or flicker back and forth between being bright and dim. The dash lights, console lights, and dome lights did the same, simultaneously.
Does this sound like a failing (or maybe just dirty) voltage regulator? I checked the battery when I got home; it was cool and dry and not bulging at all, so I'm guessing that the periods of bright lights were normal voltage and the dim times were less-than-normal voltage (as opposed to the dim times being normal and the bright times being higher-than-normal voltage). It was 3 AM so I didn't spend any time trying to diagnose it with a voltmeter.
Can I visually inspect the voltage regulator for any clues, or will a visual inspection not give me any information? From reading other posts, I gather that I don't need to pull off the whole aternator to get the voltage regulator off... not that it's terribly difficult to get the alternator off and on. If I remember correctly, this alternator is one that I got from a junker about 25,000 miles ago, and it seemed OK when I had it tested.
'83 240D, 250k miles