It could be the amplifier.. You can get them from a Junkyard limited (or Laredo if it had it) for like $10.. I found the original amp in a 5.9 for my 5.9 which previous owner took out.. its 180watts.. I think yours is something like 90 or whatever got mine for 10$
However it could be bad wiring... My 98 Laredo has no amp, just the head unit and the front speakers don't work very good anymore like no sound coming from them... It just be bad speakers I know is bad so I unplugged it
2013 6.2 V8 Camaro SS 3,000 miles :-)
1998 5.9 V8 Limited Platinum ZJ 151,xxx miles
1998 4.0 I6 Laredo ZJ 207,xxx miles Yay !