I've had two battery drainers lately.

#1 glow plug relay was on while running. 12.8 volt reading while running, but only lasted for about 100 miles then died.

Automatic antenna was broken and it stil thought it was on duty ready to run. So it was draining power while the engine was off. As I recall it was fuse #12 on a 1982 300 D.

Hope it helps

__________________
1984 280SEL, 62,000 miles
Euro model in the USA
1983 300D (Totaled out 10/2004)
New Factory Mint Green paint
Palomino int
1982 240D (Steak dinner for two)