The problem with the audio must be a problem with how the speakers are connected. You do not need to turn on the internal amplifier in this radio, it is always on. You said you connected the four speaker wires to the two speakers. You may have used the wrong wires. The front speaker wires from the radio are the white, white with black stripe for one speaker and the grey, grey with black stripe for the other front speaker. make sure each speaker you are connecting has the matching colors from the radio connected to it. meaning that one speaker will have a white wire and a white with black stripe wire, the other speaker will have the grey wire and the grey with black stripe wire. The purple and green wires should be seperated and insulated off from each other so that nothing can touch them that has any conductive surface.
The red led indicator is just for knowing that the radio is on. No other function for that. The muting for these is called "ATT" for attenuation and is located in the top left of the face.
make sure your speakers (terminals only) are not grounded to the chassis of the car, this can blow up the internal amplifier of the radio and this can result in no sound. If you can measure the voltage of the speaker wires coming out of the radio, they should measure at about 6 to 7 volts. If any one of the 8 speaker wires is not at that level, you have a blown amplifier IC in the radio. They all should measure the same give or take a few millivolts, if not the amp is bad.
Let me know if this help you at all. and a good rating would be appreciated for this free help.
on Jun 13, 2013