8. In Case of Dif�culty
Power-on light does not come on � Head unit not on; turn the head unit on. � Ground wire is disconnected or defective; check for continuity with an ohmmeter between the ampli�er�s ground terminal and a known chassis ground point. � Battery wire is disconnected or defective; check for approximately +12 volts between the ampli�er�s battery and ground terminals. � Blown fuse; check ampli�er�s fuses located on the end panel near the power connector. If they are blown, replace them with identical ones. If the new fuses blow immediately, check all the wiring connections. If the source of the problem cannot be determined, consult your JBL dealer. � Remote-on wire between the head unit and the ampli�ers is disconnected or defective; check for +12 volts between ampli�er's remote-on input terminal and the ground wire with the head unit on. Power light is on, but no sound is heard from some or all of the speakers � Incorrect switch settings; make sure that all switches (mode, input and crossover) are in their correct positions for your system con�guration. � Incorrectly connected or shorted speaker wires; check for shorts in wiring. � Defective or disconnected audio cables; check for continuity and replace if necessary. � Incorrect gain adjustment; verify that the ampli�er gain controls are not turned completely down. If they are, sound output level may be very low and may give the impression that the system (or part of the system) is dead.
Power light is on, but no sound is heard from some or all of the speakers � Defective head unit or signal processor; check each component for proper wiring and operation. � Defective GTQ ampli�er; if there is audio signal present at the inputs of the ampli�er and there is no output, the GTQ ampli�er may be defective. Alternator whine through the audio system with the engine running � Ground loops; follow the wiring suggestions in the section called �Solving Noise Problems.� Also, verify that the chassis grounding point you have chosen is true ground by checking for continuity between the chassis ground point and battery ground. Bass output from speakers too low � Speaker wired out of phase; check for proper polarity on all speaker wiring (+ amp terminal to + speaker terminal and � amp terminal to � speaker terminal). Power light is blinking and no sound is heard � Incorrectly connected or shorted speaker wires; check for shorts in wiring. � Defective GTQ ampli�er; if there is no short on the speaker outputs, the GTQ ampli�er may be broken. Consult your JBL dealer.
