My car stereo

Depends on what audio system you have . Base , upscale etc.... You need to look on the RPO code sticker , could be in the glove box , center console , trunk , driver door jam ? RPO - regular production order .

UL0
Radio AM/FM Stereo, Seek/Scan, Auto REV Music Search Cass, Auto Tone, Clock, ETR
UM7
Radio AM/FM Stereo, Seek/Scan, Clock, ETR
UN0
Radio AM/FM Stereo, Seek/Scan, Compact Disc, Auto Tone, Clock, ETR
UN6
Radio AM/FM Stereo, Seek/Scan, Auto Rev Music Search Cass, Clock, ETR
UP0
Radio AM/FM Stereo, Seek/Scan, Auto Rev Music Search Cass, CD, Auto Tone, Clock, ETR

If you have volume but cannot control it, this is a common problem. The volume is optical so it may just have dust in it, but I have had zero luck cleaning them. The only solution I know is to replace the whole head unit.
If you have an HK factory stereo with no volume at all, and the four channels went out one at a time, the amp in the trunk has failed. Another common problem. The amp is on the driver side above the wheel well. You have to remove the driver side rear deck speaker to get the trunk lining off without tearing it. The screws that hold in the speaker are beneath the speaker grill in the rear deck. Good luck getting a 15-year-old speaker grill up without breaking the snaps. Slide a putty knive in from the sides to try to release them, but they will break anyway.
If the amp has failed, you can just bypass the amp but you will have no subs or tweeters. I did that while looking for a good deal on a junkyard amp. You can buy a new HK amp from BMW but they are prohibitively expensive. You could buy an alternate brand amp and add crossover circuits to power the subs and tweeters if you are really handy with electronics.

If you have an HK system in your BMW and you replace the head unit, use the antenna power wire from the new stereo as the 'on' signal for your HK amp in the trunk. Your FM may not work quite as well because the BMW head unit communicates with the antenna amplifier. Also, if you have a BMW CD changer in your trunk, no other head unit will communicate with that other than the original BMW head unit.
Other than the CD changer and the antenna amplifier, the wiring adapter that you can get from Crutchfield or from Amazon will make the stereo head unit replacement plug-and-play.
You may need a special five-sided wrench to get the old stereo out. You can buy that wrench on line if you can't force some other tool into those two cap screws that hold the stereo in.

verify your amps input. hook up a portable cd player with a headphone to rca "y" adapter to the amp and try that, to make sure it isnt an issue with the reciever/cd deck oir the input circuit. if the amp works correctly with the protable cd player/ walkman.mp3 player whatever, instead of the car deck, then something is wrong with your decks audio output. if it does not work with a secondary input device then perhaps you have the power hooked wrong. there should be both a red and yellow power lead from the amp, the red should be connected directly to the battery, and the yellow to the "acc on" (any circuit that turns on only when the car or stereo is turned on, sometimes connected directly to the stereo). both can be connected directly to the battery, but the yellow would need a switch, in that case, to turn the amp off when not in use.

I had the same problem when I changed out the factory cd player. I finally found the problem was that grand am gt cars have a couple of amplifiers with crossovers in them for the speakers and the after market stereos put out sound that has been slightly amplified already and when you hook up your new stereo to the wiring harness your sending amplified sound from your stereo the the factory amp then to the speakers this sometimes messes with he sound and clarity of the sound. My car is 2002 and the factory amps are located 1 under the glove box and 2 in the trunk behind the carpet on the drivers side. The amp and crossover in the front is to split the signal for the door speaker and the tweeter by the mirror and the amp in the trunk is to split the signal for the two way speaker in the back by the back window witch if they are like my factory speakers have 2 wiring harnesses connected to each speaker. the only way I could get mine to sound good was to run new wires from your stereo directly to the speakers and bypass the factory amps. This may not be the only way to fix this issue but it was the only way I could figure it out. I hope this helps

Since the mixer has a line level output, yes you can use a home stereo for the "AMP". Use the AUX IN, TAPE IN or CD IN on the stereo and connect the speakers as you normally would.

Dan

DOES THE RADIO PLAY? HERE ARE THE FACTORY WIRING COLORS FOR THE RADIO HARNESS, RECHECK YOUR WORK. IF U FIND NOTHING THEN IF THE RADIO PLAYS THE CD PLAYER IS DEFECTIVE, IT HAPPENS BELIEVE ME.

2001 Chrysler 300M Car Stereo Wiring Diagram
Car Radio Battery Constant 12v+ Wire: Pink
Car Radio Accessory Switched 12v+ Wire: Red/White
Car Radio Ground Wire: Chassis or Strap
Car Radio Illumination Wire: N/A
Car Stereo Dimmer Wire: Orange
Car Stereo Antenna Trigger Wire: Orange/Red
Car Stereo Cell Phone Mute Wire: N/A
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: Located under the rear deck in the trunk.
Car Audio Front Speakers Size: N/A
Car Audio Front Speakers Location: N/A
Left Front Speaker Positive Wire (+): Dark Green
Left Front Speaker Negative Wire (-): Brown/Red
Right Front Speaker Positive Wire (+): Violet
Right Front Speaker Negative Wire (-): Dark Blue/Red
Car Audio Rear Speakers Size: N/A
Car Audio Rear Speakers Location: N/A
Left Rear Speaker Positive Wire (+): Brown/Yellow
Left Rear Speaker Negative Wire (-): Brown/Light Blue
Right Rear Speaker Positive Wire (+): Dark Blue/White
Right Rear Speaker Negative Wire (-): Dark Blue/Orange

ok check for good earth and also check you 12v constant 12 acc... aslong as you have all three it will work...

Estas seguro que tu amplificador esta funcionando bien ya que puede ser el causante si sus amplificadores de audio estan malos.Checa eso.

You can't find faceplates for card decks since that will defy the safety feature.

gray is front right
purple is rear right
green is rear left
white is front left
the black striped ones are negative for each set.