The fact that I was able to generate a 130A load says a lot, compared to the 70A (peak!) output from the stock alternator. The designers did an ok job for the stock vehicle, at that time. In the early 80's, a 70A unit was ok. You'll note that most 124's were up to 110-120A alternators by the end of production in 1995. In the early 80's, high-output alternators were rare to nonexistent, so MB didn't really have anything larger to put on, nor any need to, at the time.

Anyway, my high beams alone (400 watts total) pull over 30 amps. The three Soundstream amplifiers are rated at 2000 watts total, with peak current draw in the 50-75A range (although typical current draw is relatively small, 10-20 amps at normal levels). Extra lights + extra stereo = Need Bigger Alternator.

Even with a bone stock vehicle, some of us don't like yellow headlights at idle, for example with the AC on high and the auxiliary fan running, on a hot summer night. Every 1980's MB I've owned with a stock alternator (and no additional loads) does this. I don't need to spend time justifying this upgrade. If anyone disagrees, hey, you're entitled to your opinions. I'm just sharing the info for the benefit of those who also need extra electrical power delivery. For example, the veggie oil crowd often add electrical heaters, which would easily overwhelm a stock alternator.