I had a battery killer once. We couldn't find the problem, until I went to the customers house, where the car was dead, and saw the brake lights on when I pulled up. The owner would shut off the car with the brakes on, and the car still in gear. Then, they would put it in park and release the brake pedal.

I ended up adjusting the brake light switch on this car.

It's time to disconnect things on the car... one at a time, until the light goes out, then troubleshoot what's out.

It can be a royal pain, but hopefully, it won't be a hard fix.

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My first Mercedes Benz. 4/6/07.

1984 190E (201 024) 2.3L four.