Audio Systems: No sound at all, dodge ram 1500, infinity sound

Question
I have a 2004 Dodge Ram 1500.  My question is:

1. If the radio turns on (lights up) BUT no sound hits the speakers...is that a radio problem? I say that because if the amp is still working, sound should still hit the speakers if the head unit is working properly...right?

2. Radio turns on, no sound to speakers....does this mean that the factory amp is blown?

So which way of thinking is correct #1 or #2?

This will determine which wiring harness for an after market radio will be used. either the METRA 70-6510 (used for question #2, works hands free behind the steering wheel.) -OR- the METRA CHTO-02 (works for question #1)


Answer
If you have the infinity sound system , check the amplifier first,
if ok maybe there is no power,check the amplifier fuse at fuse box ,there is 2 fuse box in the vehicle if ok there is a relay that activates the amplifier it is on the right side of the factory radio
this is the case with infinity sound systems

for regular radio ,it is just a bad radio
good luck