95 E320 radio antenna problem

Hello from Atlanta!
This problem came with the car when I bought it 5 yrs (232K mi.)ago. The antenna goes up and down, both with the car running and with the key out and radio off. Assume there's a short, and wonder where to start. Your help would be appreciated.

Is it an aftermarket radio?  Even if it is, there's a blue wire behind your radio, and that wire is the power antenna trigger.  Basically, if you give it 12V, it goes up automatically, and if you remove 12V, it goes down.  Make sure that whatever radio you have in there is wired up from Radio's antenna output to the blue wire on the power antenna trigger.  From the sound of it, it's hooked up to the ignition switch trigger and not the power antenna trigger from your headunit (Radio).
 
take care,
-mar-

Thanks MasterBenz,
Its a Becker and I'll start with that blue wire. Can you tell me where I can find the colors for the ignition and radio antenna wires, or a wiring diagram?

The models wiring color code differ from one another, but the antenna trigger is the same.  You have the check it using a DMM (Digital Multi-meter). 
 
take care,
-mar-

Thanks again. Have a great Sunday!

No problem...you too!
 
take care,
-mar-

Well, it's been three days and the radio, speakers, and antenna have been working perfectly. I had checked the blue wire to the antenna motor and made sure it wasn't touching any metal, cleared away the salt that had buried the phone jack in the armrest, and reinstalled the front left dash speaker that was making a popping noise. I'll keep my fingers crossed for a while longer.
Thanks again for the help and direction.