Possible Causes
WARNING: This page is about a different car, the 2005 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.
DETERMINE FAULT
LEFT I/P SPEAKER
LEFT FRONT DOOR SPEAKER
RIGHT I/P SPEAKER
RIGHT FRONT DOOR SPEAKER
LEFT REAR SPEAKER
RIGHT REAR SPEAKER
(+) CIRCUIT SHORTED TO GROUND
SPEAKER SECTION OF RADIO
(-) CIRCUIT SHORTED TO GROUND
SPEAKER (+) & (-) CIRCUITS SHORTED TOGETHER