My '88 300e has the unusual property of flickering or 'pulsing' of all lights, interior and headlights, at a subtle amplitutde yet at a constant frequency. id almost swear it affects the rpms of the engine itself, though its so minor in effect. the battery is charging, and the car runs fine.
I did a search on flickering lights here, but the issues concerned specific equipment, not a 'system wide" scenario. Ive checked the obvious, loose wire, changed fuses, etc.
volatge regulator?

suggestions welcome!

Alternator.

I think the early W124 models had underpowered alternators anyway, and as they get weak, the accessories are the first to get starved of juice.

I believe that the voltage regulator is built internally in the alternator anyway.

You are probably getting a nominal charge to the battery, but it's only going to get worse. When it does, the engine management systems get affected, and your car will act like it's in limp mode.

Have your charging system checked to make sure, but I'm not sure it's detected at an early stage. I had an alternator once that checked out fine, only to have it fail a week later...

__________________
2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car

Could there be a rectifier problem in the alternator? If some of the diodes are not open-circuited, you'll lose charging capacity and you may get more 'pulsing' of rectified AC.

It might be in the voltage regulator, but I can't think of what would cause it to pulse.

Can you have a tech put a charging system tester on and let you know capacity, etc.?

My $0.02

BCingU, Jim