W124 acts the same way
Had a similar set of circumstances befall my 300TE. Thankfully it got me home, though! In my case it was the alternator, so it was nice to see that what little was left in the battery was used to keep the engine running, and keep the headlights on. Nothing else, though!
"If everything seems under control, you're simply not going fast enough" --Mario Andretti
1995 E500 street car
1986 Porsche 944 Turbo S track car