I just bought an 85 300D turbo and have an obnoxious trumpet sound coming from the antenna area. Last time I had it, I stopped my car and got out and located the sound to be coming from the antenna general area. I could even feel a vibration if I put my hand over the antenna. Strangely the antenna works fine, goes up/down when it's supposed to and tunes my radio perfectly. I'm new to these cars, so maybe this is common, but I didn't see anything when I searched the forum. Any thoughts?

I'll reply to my own post just in case someone else does a search for something similar they can learn from my incident.

In front of the antenna motor is round cylindrical motor which I believe is actually just an old alarm. Usually these are found in the front of the car, but this install seems unique in that respect. I disconnected the power to this motor and so far so good. All of the lights are working propperly and brakes too. After disconnecting the antenna stayed up and retracted when I shut of the car. When I saw my wife driving away this morning I didn't see the antenna go up, so it could be that there will need to be some rewiring back there to get the antenna fully functional.

I had a similar thing in my 85 300D. When my sunroof switch sticks in the 'close' position, I get a horrible squeal from that area the next time I start the car. The sunroof motor is right next to the antenna motor. I'll bet that's what you're talking about. I can see why you think it is an alarm. That sucker is LOUD.

Also, in mine, the antenna won't go up until the radio is turned on. Might be she just didn't have the radio on.

I just bought a 1995 300d, when I picked it up the sunroof would open but not vent open at the back- I wasnt worried about that. A day later I was driving with the sunroof open and this horrible squealing noise started. I pulled over and thought it was the antenna motor until I closed the sunroof and it stopped.

Problem is the sunroof won't close all the way now. WHen I move the switch I can push it open with my hand and it makes some kind of noise but it won't close.

Now I see that the motor is back there- did I burn it out or is there something else I can check? At this point I care more about getting the darned thing closed than it working....

I think there is supposed to be some sort of crank that you can use to manually crank the sunroof closed. I've never had to use it, so I don't know anything else about it. Something for you to look into though.

Chas

I would clean out the sunroof switch at the dash, reconnect the wires in the trunk, and see if both the antenna and the sunroof are now operational.

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

Sorry I never got back to finish posting my Results! Thanks Jbaj007 and bkeese. It was the sunroof motor in the back by the antenna. I disconnected it and that solved the problem. I'll have to clean out the switch b/c that makes sense that it would be going off like that due to a faulty switch. For now, just keeping it disconnected is a relief.
-Chas