BE–108 BODY ELECTRICAL SYSTEM – AUDIO SYSTEM 29 Amplifier WOOFER SPEAKER DOES NOT WORK Is power amplifier operating normally? Yes Radio receiver assembly faulty. No Is hiss produced by non–functioning speaker? Yes Radio receiver assembly faulty. No Is there continuity in speaker wire harness? No Speaker wire harness faulty. Yes Temporarily install another speaker. Functions OK? Yes Speaker faulty. No Woofer amplifier faulty. 30 Noise NOISE PRODUCED BY VIBRATION OR SHOCK WHILE DRIVING Is speaker properly installed? No Install properly. Yes Is each system correctly installed? No Install properly. Yes With vehicle stopped, lightly tap each system. Is noise produced? Yes Each system faulty. No Noise produced by static electricity accumulating in the vehicle body.