Passenger compartment temperature sensor

PASSENGER COMPARTMENT TEMPERATURE SENSOR

This is on the right hand trim on the driver's side of the dashboard.

It is an NTC sensor (R at 25°C = 2.2 kOhm), with operating range from +5°C to +45°C.

The sensor is "ventilated", i.e. inside it incorporates a small fan that is always supplied so that the temperature reading is not affected by the air stagnating inside the dashboard which would give an unrealistic result.

MAX DEF FUNCTION SWITCH

A special switch activates the MAX DEF function: this is located on the distribution knob; it is an N.O. contact which is closed with the knob turned completely clockwise.

ELECTRIC MIXING ACTUATOR

The temperature of the treated air is adjusted by suitably controlling the mixing actuator between hot and cold air which acts on the port which sends or shuts off the flow of incoming air on the heater radiator, crossed by hot water leading from the engine. A motor supplied at 12V controls the rotary movement of a draw pin which acts directly on the mixing port. A potentiometer detects the actual position and acts as "feedback" to the control unit.

RECIRCULATION ELECTRIC ACTUATOR

Rotation of the outside air inlet port is obtained by suitably controlling the recirculation actuator which acts on the port itself passing from the "dynamic air" position to the "recirculation" position. There are NO intermediate positions. A motor supplied at 12V controls the rotary movement of a draw pin which acts directly on the port. Reversing the polarity, movement in the opposite direction is obtained.