I put in my left rear 6x9 last week and everything worked fine. I put the other in on the right side today and went to listen to music and now there is no sound at all from the left side of the car. Anyone know what could have happened?

I have a pioneer head unit
Stock door speakers
Pioneer tweeters
And Rockford Fosgate 6x9's

 

Either your fade is all the way to the right, or the wires in the back of the head unit may be loose