I have 1991 300SE w/Becker 1432 system. The passenger side speakers all went dead. I thought it was the right side amplifier under the upright back seat. Well the amps are O.K. .

Could that tuner box 001 820 9289 in the trunk be the culprit or the Becker head unit in the dash? I am pretty sure the fader is all right. Help !

Despite the spam, I think the amp is your problem. Good news is the amps are the same on all the 89+ cars.

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

The amps both checked out as O.K. . Thats why I posted the question about the tuner in the trunk or the head in the dash to see if anyone had this experience in their life. (Don't you hate that spam)

You can get a small speaker and check the output at the tuner in the trunk. See if both channels are working...

-J

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Compu85...Thanks for the input but wont that just test the amplifiers? I know they work caused I swiched them. And even if I tested the tuner as you indicate how would that tell me whether it was the tuner or the head?

There are several stages of sound in that car... the FM tuner chip lives in the tuner unit in the trunk. Its auto output goes through a line selection / EQ chip, then out to the preamp unit screwed into the top of the tuner. That has a higher than line level output, which goes to the amps behind the rear seat.

If one whole side is dead, you need to be sure the tuner's preamp is spitting out signals for both sides. If it is, I'd look at the fader in the center console next.

I don't think any audio for the radio passes through the head unit.

-Jason

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Compu85 -Do you know if I could take a voltmeter reading on each the 3 prongs of the tuner output unit and what should I expect for each prong? Thanks.