I recently acquired a 1992 240 wagon. I don't have all of the service records so don't know the alternator's history. I have noticed that the headlights & dash lights pulse very slightly & quickly when you can see them at night so was thinking I should investigate the voltage regulator brushes. Then last night when I started it the charging warning light began to glow slightly. When I started driving it began to pulse slightly brighter with a period of about once every 1-2 seconds. I drove for 10 minutes to my first destination and when I started the car again a few minutes later it again started to glow and pulse. Then after a couple of minutes it went out and did not reappear during the two and a half hour drive home. I don't think this vintage car should have the same wiring problems that I had with my 1985 for which I had to build a new engine harness. I cleaned all of the interior fuse connections when I first got the car as I know that is often an issue. The only thing I can think of is the voltage regulator but why would it pulse with a period of about 1-2 seconds. Anyone have any thoughts on this?