Just picked up a 1981 280 SEL sedan ( grey market ) .
There is also a voltmeter wired on the car by one of the previous owners.
My guess is they installed it due to this issue and they couldn't figure out the problem and used it to keep an eye on the volts.
The car has a new good Mercedes Benz battery and a new Bosch Alternator.

Still when I drive even with no accessories on the volts read between 12 and 13 max. When I come to a stop it drops down to 12 or lower. If I use the AC it drops lower. I got stuck 2 days ago in the rain using the AC, wipres and headlights together. The volts dropped to 5 at a traffic light and after parking the battery was dead. After a AAA jump I was ok. he starter is good. The battery and alternator are new. Any ideas what can be draining volts on this car?

* Originally this was a well taken care of Benz but also was an up north car in Chicago and Buffalo NY so there is some rust from salted roads but not "rust bucket" condition. I know that road salt can effect electrical contacts under the car.

Again, any help is appreciated.

__________________
'87 924S
'81 280SEL

Sold ->

81 300SD -
93 300E w/ 3.2
85 300D-
79 300SD
82 300CD
83 300CD - CA
87 190E 5 spd
87 Porsche 924S

"..I'll take a simple "C" to "G" and feel brand new about it..."