Assumption:

When the ignition switch is turned to the ACC or RUN position, the radio, Tape Retract Module (TRM), the Video Cassette Player (VCP), the Auxiliary Video Module (AVM), the video screen and the Rear Seat Audio (RSA) control receive voltage, however none of these components are active (or turned on).

Assumption:

When the video screen is placed in the down (viewing) position, a position switch inside the video screen closes and sends a voltage signal to the AVM. The AVM turns on and also turns on the backlight on the video screen.

Assumption:

The VCP sends a video image signal to the AVM. When the AVM is in the VCP mode, the AVM sends this video signal to the video screen, and produces images.

The VCP also sends stereo audio channels to the AVM. Then, the AVM produces two outputs, one set with a low loudness level for headphone use, and another one that is amplified for the rear speakers. The AVM routes the video audio channels through the Interface Module (IM), which are bussed and distributed to the Second Seat Audio (SSA) and Third Seat Audio (TSA) controls. The AVM sends the amplified video audio channels to the IM, which are then routed to the rear speakers.

Assumption:

When the Interface Module (IM) senses that the radio is on, the rear speakers are muted.

Assumption:

The radio enables the Rear Seat Audio (RSA) when the RSA control is turned on. The RSA enabling circuit is sent to the RSA controls, Second Seat Audio (SSA) and Third Seat Audio (TSA) controls. When the user selects AUD mode on the SSA or TSA control with headphones connected at the SSA or TSA, audio selected at the RSA control can be heard through the headphones.