[Em3297]

Hi guys I am a new owner to a W124 that was given to me for free because it would not start. I got the car running like a top and everything is going great. I fell in love with the car, becasue of the high quality materials and just the way it drives and character of the car. Im a BMW mechanic but this thing is better then anyhting ive owned haha!

Recently I dropped the rear pneumatic headrests while driving and the radio stopped working. Specifially what happened is all the functions of the radio work but only static comes out through the speakers. Sometimes when I first turn on the car on the radio will work for a couple of seconds then fade out into static. One wierd thing also is before this static thing happened, when i would put in a cassette to play aux audio from, it would just spit out the cassette. Before it would play audio from it.

I know the radio was working before, so I dont think it could be the headunit or speakers, Im thinking it is the amplfier? I located it its in the passenger side trunk behind the trunk lining. Any help or advise on this would be much appreciated. I have learned a lot from these forums, and from people discussing. So I would like to docuiment all of my progress from this moment on to help any future w124 and mercedes owners.

Respect and Thank you,

Emanuele Agolli
6/20/2020, New Jersey USA

 

[Real1shepherd]

That's a real hornet's nest. I don't know what you mean by "pneumatic headrests"....the headrests are all driven up & down on a geared track by an electric motor. Obviously, if running those caused the static on you radio, you have a short to ground, wire worn bare etc. etc. And just because the HU was working before, don't assume that it and the amp(s) in the back can't go to sh*t at anytime given their age.

Unless you get lucky, you have a lot of diagnostic work ahead of you.

Kevin

 

[Em3297]

Ah I see I thought they were pneumatic. Nevertheless, you are right I do have some diagnosing to do. I will check it out and reply if I have found anything.
Thank you for your response Kevin.

Emanuele

 

[Floobydust]

What year is your W124? Over the years, MB fitted several different radios, one with a remote tuner. Also, while I don't have a sedan, I know that front head rests are electric, but always thought the rear head rests were vacuum operated.

 

[Real1shepherd]

Ah I see I thought they were pneumatic. Nevertheless, you are right I do have some diagnosing to do. I will check it out and reply if I have found anything.
Thank you for your response Kevin.

Emanuele

Flooby may have a point on the rear headrest in a sedan. I don't have any adjustment in the TE....they just pull up manually. Not sure if there was ever an option on a TE for that.

Yeah, dig into it some more and tell us what yr you have. Some had the 'bass boost' set up, some had two amps and a tuner in the back.....some had one amp and a tuner in the back etc. Facelift cars had none of that but a conventional HU with built in amps like most of the world.

You could run your VIN to see what sound system was supposed to be in your car.

Kevin

 

[LeftCoastGeek]

on the 124 sedans, the rear headrests can be dropped by a dashboard switch, and the dropping mechanism is vacuum operated. they can't be raised back up remotely, your rear seat passengers have to lift them up..

no sane reason this would affect your stereo unless there's some bodged wiring involved.

there's two different factory speaker setups on US model 124's... most cars got 'active bass', V8's and select sedans and couples got 'sound system' aka 'bose'.

activebass uses a small amplifier in the trunk for midbass woofers in the lower front doors, everything else is driven off the radio directly.
sound system has TWO amps in the trunk, one drives all 3 left side speakers (dashboard, front doors, and rear parcel shelf), and the other drives all three right side speakers.

now, depending on the year, you can have several different radio setups with either of these...

1) single piece radio in dashboard, with a fader on the center console. this radio has just left+right outputs, and the fader splits this into front and rear
2) single piece radio in dash with no fader
3) two piece radio where the dashboard is just a control panel and cassette mechanism, and the bulk of the radio and audio electroncis is in the trunk. I am not sure if these were before or after the fader was dropped, which was in 1994

 

[Real1shepherd]

No 3 is what I have in the '92 TE. I have the Becker in a house closet that came out of that configuration and is 100% functional......cassette and all. The rest of the rear units were cobbed by the PO and a auto audio shop on my original TE.

Kevin

 

[Em3297]

Hi guys so just to update you on what happened. I have the Becker headunit. Stock all original. My issue was the radio would turn on but no music would play just a faint static noise. Sometime I would be able to hear faint music but then it would quickly disapear into static. My cassete aux wasnt working either, I would put the cassete in and it just spat it back out.
So I removed the headunit out by simply removing the 2 screws from the ashtray and pressed 2 clips the headunit was able to be pulled out. I found one wire disconeccted or loose. I gave everything a quick clean and I made sure everything was ok. Radio seems to be working great now no issues.

FYI these are old cars check for loose wiring and corroded terminals. Thanks for the help.
Manny