Rear speakers not working - Dell 5650 Computer Speakers

First, check the fader on the stereo, then, check the wiring from the stereo to the amp and from the amp to the rear speakers. The amp controls all speakers, not just the rear so it seems that it is still working therefore the fuses must be good. If you have access to any other speakers, I would try plugging one in in place of one of the rear speakers and seeing if it works then you'll know if it's just the speaker or not.

It should have a balance nob on the face of radio front and rear,make sure wires are plugged on to speakers.

look under back seat for preamp

1997 Chevrolet Tahoe Car Radio Wiring Diagram
Car Radio Battery Constant 12v+ Wire: Orange
Car Radio Accessory Switched 12v+ Wire: Yellow
Car Radio Ground Wire: Black
Car Radio Illumination Wire: Gray
Car Stereo Dimmer Wire: Brown
Car Audio Front Speakers Location: Doors
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
Car Audio Rear Speakers Size: 6 1/2? Speakers
Car Audio Rear Speakers Location: Rear Doors
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 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

reinstall ur sound and video program

This may be a software issue. If you only had two speakers before, the software will not use the rear speakers.
Go to Control Panel. Click on "Sound and Audio Devices". Under the Volume Tab, at the bottom, you will see a picture roughly representing the type of speakers.
Click on the Advanced button.
Click on the arrow in the pick box, and choose Surround Speakrs or the 5.1 Speakers.
Click Okay. Try the speakers again.

1997 Hyundai Sonata Car Stereo Radio Wiring Diagram
Car Radio Constant 12V+ Wire: Red
Car Radio Switched 12V+ Wire: White/Green
Car Radio Ground Wire: Black
Car Radio Illumination Wire: N/A
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger: N/A
Car Stereo Amp Trigger Wire: N/A
Front Speakers Size: 4′
Front Speakers Location: Dash
Left Front Speaker Positive Wire (+): Brown/White
Left Front Speaker Negative Wire (-): Black/White
Right Front Speaker Positive Wire (+): Brown/Yellow
Right Front Speaker Negative Wire (-): Black/Yellow
Rear Speakers Size: 6 1/2′
Rear Speakers Location: Door
Left Rear Speaker Positive Wire (+): Brown/Red
Left Rear Speaker Negative Wire (-): Black/Red
Right Rear Speaker Positive Wire (+): Brown/White
Right Rear Speaker Negative Wire (-): Black/Whi

You need to attach the blue wire on the stereo harness to the blue and white wire on the car adapter harness. they installed a small amplifier to power the rear door speakers and unless you connect those two wires then the speakers will not work.

If you did the 5.1 sound test and the rear speaker works, sometimes you have to see in your software speakers settings,probably you need to change to 5.1 speakers