Normal Operation
WARNING: This page is about a different car, the 2005 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.
Voltage is sent to the audio unit for the start input through circuit 50-MD15 (GY/OG) when the key is placed in the START position. The audio unit then immediately mutes all speaker amplifier outputs and the subwoofer amplifier enable circuit to eliminate the possibility of speaker pops during engine cranking.