Test F

PINPOINT TEST F: LOUD POPPING SOUND WHEN CYCLING THE IGNITION SWITCH

Test F1:

Normal Operation
The START input circuit 168 (RD/BK) is sent to the audio unit when the ignition switch is turned to the START position. The audio unit then immediately mutes all speaker amplifier outputs and the subwoofer amplifier enable circuit output to eliminate the possibility of speaker pops during engine cranking.

Possible Causes
- circuit 37 (YE) open
- circuit 168 (RD/BK) short to power
- subwoofer amplifier