1987 300D Radio diagnosis - PeachParts Mercedes-Benz Forum

renaissanceman · #1 12-11-2014, 09:15 PM

Hello all, and my apologies for all the simplistic questions as I learn about and restore my newly purchased 300D. There will be more to follow as I get this thing back to like new shape! Thanks in advance for the guidance.

I finally had some time to look at the stereo on my car, and here's what it's doing:

It powers on and off fine, all the functions seem to work (fading, tuning, tone adjustment, etc) but both the AM and FM just pump out static, not even a faint station. The automatic antenna does not extend, no matter what of the 3 positions I have the rocker switch.

I just bought a tape deck adapter, so I'm going to try the tape function to see if I can get some sound from that. Any thoughts?

jay_bob · #2 12-11-2014, 10:21 PM

I suspect your lack of antenna extension is causing the radio static.

On the back of the radio (I assume you have a Becker 780) there is a single blue wire with a quick connect. It has a black sheath on it so you may mistake it for a black wire.

Make sure that is plugged into the radio. It goes next to the power connector.

In the trunk make sure the connector is plugged into the antenna.

Antenna is fed from fuse C but if your dome lights and door locks work that isn't your problem.

renaissanceman · #3 12-12-2014, 03:06 AM

Dome lights and locks work. I have not checked the antenna connections yet. I got knocked on my butt by some type of cold bug today, so all the projects went on hold.

eatont9999 · #4 12-12-2014, 08:00 AM

It is common to have to clean/rebuild the antenna motor and install a new mast. Can you hear the motor for the antenna when you turn the radio on?

renaissanceman · #5 12-12-2014, 03:53 PM

Quote:

Originally Posted by eatont9999

It is common to have to clean/rebuild the antenna motor and install a new mast. Can you hear the motor for the antenna when you turn the radio on?

I have not noticed any sound from the motor in the past, but I can't be sure. I was running a 102.5 fever this morning, so I'm currently on rest orders from my doctor, so I probably won't be looking into it for a couple days.

Guest987 · #6 12-12-2014, 04:47 PM

There is a car audio and multimedia section on this forum. You might want seek it out!

renaissanceman · #7 12-12-2014, 04:58 PM

Quote:

Originally Posted by Rebe

There is a car audio and multimedia section on this forum. You might want seek it out!

Oh, good to know! I'll definitely check that out! The Becker unit seems to be very high quality, hopefully I'll be able to get it going soon.

renaissanceman · #8 12-12-2014, 06:32 PM

I snuck out and tried the tape deck, and it works! I guess the head unit is still functional at this point, and I just need to sort out the antenna issues.

Quahog · #9 12-12-2014, 07:55 PM

what was the tape?

I replaced an antenna mast recently with one from a parts unit.

hardest thing was separating the mast from the body, the rest was tedious unwinding/winding the toothed part into the body.

eatont9999 · #10 12-13-2014, 12:02 AM

Quote:

Originally Posted by renaissanceman

I have not noticed any sound from the motor in the past, but I can't be sure. I was running a 102.5 fever this morning, so I'm currently on rest orders from my doctor, so I probably won't be looking into it for a couple days.

No problem. I hope you feel better soon!

Hopefully someone just unplugged the antenna and it is an easy fix. Keep the Becker in there. I have an SD with a becker and an SD with a Blaupunkt and the Becker sounds 2x as good as the Blaupunkt. Becker Auto Sound rebuilds the units if you need it. I want to send a few of mine out to get them rebuilt so the tape deck plays cassettes. The bands and heads are worn on all of mine.