Radio

I have a 2002 PT Cruiser Limited
Editions it does not have a
factory amp the key is wore out
in the ignition sometimes it
would light up the backlighting
on the factory radio sometimes
it wouldn't I switched it out with
an aftermarket pioneer double
din now I have no sound to the
speakers all fuses are good I
tested the radio it is good I'm at
a loss can somebody help