About 4 times a year my W124 stalls while driving, almost always when coming to a stop or parking.

It cuts with no warning and all the dashboard warning lights come on, as if I had turned the key. Usually I can't tell it stalled except for the lights.

I know it could be the OVP, and I remember that there is another part that delivers electrical power that has brushes that wear down, but I can't remember what that is called, it's not the alternator.