Here's probably a real simple one for you experts: Recently lost audio on the drivers side. When using the BAL control, the audio decreases to almost to nothing when going all the way to the left. Right side seems normal. Fader sounds scratchy in left side speakers also. Pulled the rear deck speaker grille and the left side speaker magnet seems much warmer than the right. Do not want to upgrade, just want to restore to normal. Can one blown/bad speaker take out one side of the stereo? Where is the most logical place to start? Thanks; Don

1993 190E, No CD Player, Just Cassette

 

Does the radio have front/rear fader & R/L balance, four power amp outputs?

If so, then one channel of the amplifier outputs may may be blown.

Measure the impedance of the ( four? ) speakers, should be around 4-8 ohms each.

Disconnect the head unit from the harness, measure the speaker wires at the back of the head unit, should be similar impedance as the (four?) speakers.

IF your radio does not have an auxillary amplifier, then it would be the output IC in the head unit (this may be a two or four channel amplifier IC). Most likely the silicone grease to the heat sink is dried out.

Check each channel speaker output at the head amp, with a known good speaker, if one channel is dead, it's the head unit. just replace the IC.

One of these may be the Headunit pinout

http://www.budget.net/~sura/radio_pin_outs.pdf

or

http://www.beckerautosound.com/1492.html

 

Thanks for the reply M444. My head unit is the Alpine CM2191. I'll check out your recommendations and let you know. First step is substituting known good speakers. Again, thanks. Don

 

In answer to your other questions, the R-L balance is controlled from the head unit; the front-rear fader is a pot in the console.