Audio Systems: Audio System for 2001 Dodge Stratus R/T, infinity logo, fuse box

Question
I have a 2001 Dodge Stratus R/T that has a bit of a problem.  When I first got it the Radio and Speakers work just fine.  Now the Radio works (or seems to be) but has no sound coming out of it.  I have looked and looked at the wires but I am some what dumb at these things.  Is there a factory amp or something that could be messing up. Or does anybody think it is something else.  Or maybe a ground somewhere that is not connected.  Because the Radio is reading that there is a station but there is no sound coming out.  I would appreciate an answer
Thanks a bunch
Tim

Answer
yes there are 1 or 4 amplifiers in the vehicle if there is a infinity logo on the vehicles door next to the speaker grill


there is also a relay  next to the radio that powers this amplifiers and there is also a fuse for this in the fuse box outside the vehicle

good luck