Rear speakers have no sound

2002 GMC Sonoma Stereo Wiring Information

Radio Battery Constant 12v+ Wire: Orange
Radio Accessory Switched 12v+ Wire: Yellow
Radio Ground Wire: Black
Radio Illumination Wire: Gray
Stereo Dimmer Wire: Brown
Stereo Antenna Trigger Wire: Pink
Left Front Speaker Positive Wire (+): Tan
Left Front Speaker Negative Wire (-): Gray
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Dark Green
Left Rear Speaker Positive Wire (+): Brown
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Dark Blue
Right Rear Speaker Negative Wire (-): Light Blue


..

Check the bal./fader on the radio sound setting there could be a misbalance in the settings.

Check the speakers if they work. Connect the speaker terminals using a short wire to a 1.5 volt battery (AA or any dry cell batter) and listen if there's a thumping sound when the wires are connected to the battery terminals. If there's no sound, your speakers are busted. If there's a sound, check if the wires are okay. Use the same method with the battery with the wires from the back of your stereo. Make a small cut on the wire and attach the short wires you used earlier.

Hi there:
This information about 2004 Chevrolet Tahoe Car Stereo Radio Wiring Diagram could helpful:

Radio Constant 12V+ Wire: Orange
Radio Ignition Switched 12V+ Wire: Class 2 Serial Data
Radio Ground Wire: Black/White
Radio Illumination Dimmer Wire: N/A
Radio Antenna Trigger Wire: Dark Green
Radio Amplifier Trigger Wire: Pink (If equipped, the amplifier is under the center console.)
Front Speakers Size: N/A
Front Speakers Location: N/A
Left Front Speaker Wire (+): Tan
Left Front Speaker Wire (-): Gray
Right Front Speaker Wire (+): Light Green
Right Front Speaker Wire (-): Green
Rear Speakers Size: N/A
Rear Speakers Location: N/A
Left Rear Speaker Wire (+): Brown
Left Rear Speaker Wire (-): Yellow
Right Rear Speaker Wire (+): Blue
Right Rear Speaker Wire (-): Light Blue

Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using FixYa, have a nice day.

Hi there:
According with the diagram on 2004 Toyota Camry Car Radio Wiring Diagram...

Car Radio Battery Constant 12v+ Wire: Blue/Yellow
Car Radio Accessory Switched 12v+ Wire: Gray
Car Radio Ground Wire: Brown
Car Radio Illumination Wire: Green
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger Wire: N/A
Car Stereo Amp Trigger Wire: Pink/Blue
Car Stereo Amplifier Location: Located to the right of the glovebox behind the passenger side of the dash.
Car Audio Front Speakers Size: N/A
Car Audio Front Speakers Location: N/A
Left Front Speaker Positive Wire (+): Pink
Left Front Speaker Negative Wire (-): Violet
Left Front Tweeter: Powered by the same wires as the left front speaker.
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Blue
Right Front Tweeter: Powered by the same wires as the right front speaker.
Car Audio Rear Speakers Size: N/A
Car Audio Rear Speakers Location: N/A
Left Rear Speaker Positive Wire (+): Black
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Red
Right Rear Speaker Negative Wire (-): White

Tehy could be harnesses 15 or 20 pins, try to look your right replacement in this links:

- 2004 Toyota Camry Stereo Wiring Harness

- 1990-2013 Toyota Camry Auxiliary Car Audio Input Adapter Kit

Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using FixYa, have a nice day.

Did it fail while you had vehicle, or like this when you bought it? Could be bad radio or wiring harness was chopped up when previous owners had an aftermarket radio installed. They probably just slapped the OEM radio back in when selling car. And didn't put all the OEM wiring back in.

Sounds like the amplifiers in the trunk, passengers side are failing.

check wiring on passengers side near the rear hatch speaker, the rear door speakers are run through them also. i had the same problem and it was a unplugged connector at that location

CHECK REAR AMPLIFIER (INSIDE TRUNK) BAD CAPACITOR OR BAD CONNECTION. REPAIRED MINE TODAY.
COST $30.00-

could not find an amp behind rear seat as suggested
speaker seemed to be blown
however a replacement speaker (new)
made same horrible noise
3 others work fine