sure it's possible. That Ai-net cable carries among other things, your right and left stereo signals, so I would first try to wiggle it, unplug/plug it in, look for damage or bad kinks etc... If it is the cable, then don't worry too much, they're not too expensive. If you can borrow one and try it, that would an easy way to narrow it down. Go to a stereo shop and ask them.

__________________
2004 300M SPECIAL
Alpine CDA 9833
Alpine Pxa-h701
Alpine Rux-c701
Rockford fosgate p400-4
Rockford fosgate p4004
Hifonics BX 1205D
JBL c608 GTi
JBL p963
Infinity 2.5" center channel
Alpine type R 12"(2)
200 amp alternator
yellow top battery
0 awg power and ground (welding cable) 300 amp anl fuse
all active SQL set up with 2000 watts rms