For the past week I have been reading through the "archives" searching for a solution to the extremely high idle in my '91 190E 2.3 and I can't narrow it down.

I am new to the gasoline Mercedes engine. I know the diesels fairly
well.

My car will idle at 2500 rpm's and will drop to 800 rpm's when in
gear. This happens hot or cold. Also, prior to a 60 mile trip last night I
checked the fuse on the OVP and it was blown. I replaced it and it had no
effect on the idle. Of course I used the lights and other accessories
with no problems (other than the ABS light "blipping" on when I turned on
the defrost and the radio cut out but it came back on a few seconds later, this also happens when I turn on the fog lamps) but when I got home the battery was dead as a hammer. The alternator light never illuminated while driving. It does come on as it should when the car is started and goes out normally.

Thanks for your time,
Kevin