Hello all,

Have a 1990 300SL with a weird ignition switch. Worked properly for the last 6 months that I've owned the car, but has started doing something funny.

With the ignition in the "off" position and key removed, the car "powers up" by itself. The radio comes on, antenna goes up, etc. I find the car with the radio on sometimes in the morning

I put the key in the ignition and wiggled it (the key stayed in the off position the whole time.. I didn't turn it to Position I or anything). I could get the radio, door buzzer, and other electronics to go on/off by wiggling the key.

It seems if you turn the key counterclockwise to "off" when shutting down the car, then pull it out, you're ok. If you turn it any further counterclockwise than absolutely necessary to get the key out, it goes into the "accessory" position. So if you crank it all the way off (against the stop), it goes in to the accessory position and the radio comes on.

The electrical portion of this switch was bad when I bought the car and was replaced 6 mos ago. If I recall, the old one just "plugs into" the mechanical portion of the switch -- there is no alignment or anything.

Do I have a bad electrical portion, or is there something in the mechanical portion that would cause this? Neither really sounds like a possibility, since MB electrical switches don't go bad so fast (in my experience) nor do the mechanical portions of these ignitions ever go bad.

Any thoughts? Before I pay my mechanic to tear it apart again I'd like to be pretty sure it's actually the electrical switch and will be under warranty.

Thanks!
Neal

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