Car Radio Problem - Nissa Sentra - Sound comes through VERY LIGHT out of the drivers side speakers, any ideas?

This sounds like a problem in the radio. Your radio uses an IC to determine the volume, balance, fade and tone settings. It also serves as a source switch.

Audio signals from the AM, FM and CD or cassette run to this IC and are processed in route to the audio amp circuit.

Edit.

I had a radio like yours come in today with no sound from any speaker. Problem was the IC I wrote about.

Highly unlikely it is the radio. The tweeter mounted on the pillar would not operate if this is the case. I'd check the wiring to the door ... possibly you may have opened the door too wide and something somehow got disconnected and the like. Since this happened rather sudden, I doubt you blew both left side speakers together at once.

Have you checked the 'Balance' option on your radio? You could have it balanced to the right side.

Yes, it could be your radio. Often the channels are linked by side (front and rear left; front and rear right). It doesn't sound right to me though, with somthing coming out I suspect it's your balance.