electrical strangeness 300sd

Hi, Ever since I bought my 1984 300SD a number of months back, when I start my car the windshield wipers always come on for a wipe or two. I also noticed the
speedometer went up to 20 when cranking. My battery went dead a week ago and I replaced it with a new battery. Tonight this new battery died.
Any suggestions?
Thanks, Jeff
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You need to check all the circuits for a drain. That's done by removing each fuse, one by one, and checking its circuit with an ohm meter or test lamp. The one with a short or drain will light the test lamp or show resistance on the ohm meter. Only the clock is a legitimate draw.
Power antenna motors sometimes get stuck ON. You can disconnect its motor at the antenna - and still have radio if the antenna is left in an UP position.
Another possibility is a window motor that's ON due to a stuck switch.
Wipers seem to get a shot of power whenever the starter is used - somehow getting power from the start circuit or ignition switch. Anyone ever "work" on the car's wiring - to install a stereo or alarm? If so I'd first look there.
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