GM Repair Problems? Ask GM Repair Expert Now.
Hello & Welcome to JA,
the circuits from the radio & amplifier will need to be checked to make sure they are not grounded & the circuit is good.This is done with an ohm meter & a "known good" speaker should be substituted in place of each of the problem ones. If the circuits check good & no difference with the substituted speaker your problem will be in the radio. The radio will need to be removed & sent to an AC Delco repair facility for repair.