1990 2.0 190e, battery runs down when I use Air conditioner
 

Somebody help me out, my newly bought fairly used 190e (1990 model) 2.0 mercedes benz is running down my battery everytime I use the air conditioner for a while and if I stop the car, I'ld have to use another battery to start it. What's wrong? The a/c is factory fitted and the alternator came with car.

Then, the seatbelt light is no longer coming on. Even the ABS light is constantly on too.

Pls I'ld love to know what's wrong so I could fix it now.

Same prob on my 1991 190e (85K)
 

i've replaced alternator and battery.
recently i've had problems cold starting.
however, i did find a loose cable connection behind the battery (looks like a computer cable in the ovp area) and that seems to have fixed the cold start problem.

two things, first have the alternator checked for proper output. sometimes a weak alternator will be fine til you turn on a/c and accesorries and drops it's output and drains the baterry.
secondly, have the belts checked. make sure when the a/c turns on the belts arent slipping etc not making the alternator to turn the way it should.
good luck.