Technical Description

When switch 35 is in positions 1-4, current will be supplied to the Integrated Central Electronics (ICE) control module via A/C switch 169.

ICE control module 500 monitors the engine coolant temperature and if it is below 126 °C, current is supplied to the engine management system via antifrost thermostat 171 and pressure switch 166. The pressure switch is activated only when the pressure in the A/C system is above 2 bar but below 30 bar.

A/C relay 156 is grounded in the engine management system.

Current is supplied from fuse 5 in the main fuse box in the engine bay via relay 161 to the A/C compressor's overheating cut-out (thermofuse).

If compressor temperature drops below +140 °C, current will be applied to the compressor's electromagnetic clutch.

Microswitch 580 on the side of the heater housing is actuated by the air blender flap's linkage system. When the heater knob is turned to the minimum position, the switch closes and electrically controlled vacuum valve 581 shuts off the vacuum supplied to the heat exchanger valve. This shuts OFF the supply of water to the heat exchanger.