Lots of good thoughts here.
The drain is indeed big, since it kills a good battery overnight, and has the test lamp glowing at half brilliancy.

Alternator diodes sound interesting. Can I easily isolate it?

OVP relay? Again, can I unplug it? I think it is behind the battery.

I don't see any lights on overnight.


The car in question is my daily driver, 1995 E320s, with 202k on the clock. I throw two kayaks on the roof, twice a week, keep the paddler in the boot, and generally enjoy the car.
Thanks again.