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Home >> Mercury Truck >> 2005 >> Mariner 2WD L4-2.3L VIN Z >> Repair and Diagnosis >> Accessories and Optional Equipment >> Radio, Stereo, and Compact Disc >> Testing and Inspection >> Pinpoint Tests >> Audio System >> Test E: The Subwoofer Is Inoperative

Test E: The Subwoofer Is Inoperative

PINPOINT TEST E: THE SUBWOOFER IS INOPERATIVE


E1-E2:






E2-E5:






E5-E6:






E7:






Normal Operation
The subwoofer speaker is powered by a separate subwoofer amplifier. The START input circuit, 174 (GY/BK), carries out 2 functions: to turn on the subwoofer amplifier, and to indicate to the audio unit when the subwoofer output distortion signal reaches a damaging level. The audio unit then reduces the audio output signal to the subwoofer amplifier. The subwoofer amplifier receives power on circuit 720 (RD/YE), and ground on circuit 694 (BK/LG).

Possible Causes
- circuit 720 (RD/YE) open
- circuit 169 (LG/BK) open or short to ground
- circuit 172 (LB/RD) open or short to ground
- circuit 174 (GY/BK) open or short to ground
- circuit 694 (BK/LG) open
- subwoofer amplifier
- subwoofer
- audio unit
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