Amplifier: Description and Operation

External Amplifier (AS3)










General
Audio system 3 contains a separate amplifier unit that supplies the extra woofers in the front doors. The amplifier is connected to the wiring harness via three different connectors.

Function

1. 2-pin connector
The amplifier unit is powered separately (+30 circuit) from fuse 25 to pin 2 and is grounded to grounding point G34P via pin 1 in the amplifier's 2-pin connector.

2. DIN connector
- When the audio system is activated, the trigger voltage is also supplied from pin 8 in the DIN connector to pin 8 in the amplifier's DIN connector. The trigger voltage alerts the amplifier, which is then activated.
- The audio input signal (4 channels) is supplied from the main unit line outputs to the amplifier via the DIN connector. 2 of these 4 channels are used.
- Mute control is fed from pin 6 in the DIN connector on the main unit to pin 6 in the amplifier's DIN connector to switch off the sound. This is to avoid clicks in the loudspeakers when the ignition is turned on/off.

3. 4-pin connector
Audio output (2 channels) from the amplifier to the loudspeakers in the front doors via a 4-pin connector.

See Test readings, amplifier connections.