A/C Compressor

When the A/C compressor is activated, either by the A/C control module or by means of the A/C button on the dashboard, battery positive voltage (B+) is applied to pin 12 of the Motronic control module (via the Integrated Central Electronics (ICE), antifrost thermostat and pressure switch).

The control module then opens the idle air control valve slightly more to prepare for the forthcoming load increase. After a short delay the control module grounds pin 36, which is connected to the A/C relay.

The control module breaks the circuit to pin 36 if the engine has not yet been started.