Workshop Manuals Factory service & repair Alfa Romeo
01 General information02 Specifications03 Manufacturing data and tolerances04 Tightening torques05 Fluids and lubricants06 Maintenance07 Diagnostic checks08 Engine09 Clutch10 Gearbox and differential11 Axles and driveshafts12 Brakes13 Steering14 Suspension and wheels15 Heating, air conditioning and auxiliary units16 Electrical equipment17 Body fittings18 Body panels and frame19 Wiring diagrams and electrical functions20 Wiring harnesses21 Connectors and pin-outs22 Fault diagnosis23 Special tools
Alfa Romeo GT Factory Service Manual (2003-2010)19 · Wiring diagrams and electrical functions
19 · Electrical

Air conditioning - functional description

Make
Alfa Romeo
Model
GT Factory Service Manual
Year
2003–2010
Section
Climate control system › Air conditioning - functional description
Wiring diagrams and electrical functionsAir conditioning - functional description

AIR CONDITIONING - FUNCTIONAL DESCRIPTION

1.8 T.SPARK, 2.0 JTS, 1.9 JTD 16V · Two-zone climate control system

Functional description

Climate control control unit

M70 is supplied when the ignition is turned on (INT/A) at pin 25 of a line protected by fuse F31 from underfacia junction unit B2.

; it is supplied directly at pin 31 from a line protected by fuse F39 of underfacia control unit

B2.

The supply for lighting the controls with the side lights on reaches pin 24 from the line protected by fuse F35 of underfacia control unit

B2.

Pin 21 of

M70 is earthed.

Control unit

M70 is also connected to sensors K87 (right lower treated air - connector B - and left - connector A), K88 (right upper treated air - connector B - and left - connector A); these sensors receive a reference earth from pin 32 and send signals to pins 19, 20, 29 and 30 of M70.

Passenger comparment air sensor

K89 also receives a reference earth from pin 32 and sends a signal to pin 37 of M70.

Sensor

K89 is fitted with a fan motor controlled by the ignition so that the temperature reading is not affected by the motionless and thus warmer air inside the dashboard.

The solar ray sensor

K90 informs the control unit of the heat coming from rays: it receives a 5V supply from pin 38 control unit M70 and gives out two signals: to pin 39 for the right area and to pin 40 for the left area.

The exhaust gas presence sensor (A.Q.S.)

K64 supplies a recirculation control signal when the air pollution exceeds pre-set levels: it is supplied at pin 1 from the line controlled by the ignition (INT/A) protected by fuse F31 of underfacia control unit B2;

pin 2 is earthed and pin 3 sends a signal to pin 27 of

M70.

Demisting sensor

K03 is supplied at pin 2 of ignition-operated line (INT) protected by fuse F49 of underfacia control unit B2;

pin 1 is earthed and pin 3 sends a signal to pin 28 of

M70.

The air conditioning system is equipped with one recirculation actuator (

N82), two air blending actuators (N78 and N79) and two air distribution actuators (N81 and N83).

Recirculation actuator

N82 is controlled by control unit M70, via pins 1, 2, 3 and 4.

Mixing actuators

N78 and N79 are controlled from control unit M70 via pins 5, 6, 7, 8 and 11, 12, 13 14 respectively.

Distribution actuator

N80 is controlled from control unit M70 from pins 15, 16, 17 and 18.

An electronic governer

M72 controls fan N85 at different speeds via an earth command: this is ignition-operated (INT/A) from a line protected by fuse F31 of underfacia control unit B2. It receives a control signal from pin 33 of the control unit and returns a feedback signal to pin 9 of M70.

Fan

N85 is supplied directly from a line protected by fuse F5 of engine bay control unit B1.

Pin 36 of

M70 controls activation of the compressor.

The outdoor temperature sensor is located on door mirror

P60: the sensor is connected to the control unit on door H44 and thence, via the CAN network, to M70.

Pins 34 and 35 of control unit M70 connect to Body Computer M1 and node H44 via the CAN line: speedometer signal, windscreen washer on signal for recirculation activation, window and sunroof shut command, battery voltage signal, rear window on signal.

See E6021 COMPRESSOR ENGAGEMENT

3.2 V6 · Two-zone climate control system

Functional description

Climate control control unit

M70 is supplied when the ignition is turned on (INT/A) at pin 25 of a line protected by fuse F31 from underfacia junction unit B2.

; it is supplied directly at pin 31 from a line protected by fuse F39 of underfacia control unit

B2.

The supply for lighting the controls with the side lights on reaches pin 24 from the line protected by fuse F35 of underfacia control unit

B2.

Pin 21 of

M70 is earthed.

Control unit

M70 is also connected to sensors K87 (right lower treated air - connector B - and left - connector A), K88 (right upper treated air - connector B - and left - connector A); these sensors receive a reference earth from pin 32 and send signals to pins 19, 20, 29 and 30 of M70.

Passenger comparment air sensor

K89 also receives a reference earth from pin 32 and sends a signal to pin 37 of M70.

Sensor

K89 is fitted with a fan motor controlled by the ignition so that the temperature reading is not affected by the motionless and thus warmer air inside the dashboard.

The solar ray sensor

K90 informs the control unit of the heat coming from rays: it receives a 5V supply from pin 38 control unit M70 and gives out two signals: to pin 39 for the right area and to pin 40 for the left area.

The exhaust gas presence sensor (A.Q.S.)

K64 supplies a recirculation control signal when the air pollution exceeds pre-set levels: it is supplied at pin 1 from the line controlled by the ignition (INT/A) protected by fuse F31 of underfacia control unit B2.

pin 2 is earthed and pin 3 sends a signal to pin 27 of

M70.

Demisting sensor

K03 is supplied at pin 2 of ignition-operated line (INT) protected by fuse F49 of underfacia control unit B2;

pin 1 is earthed and pin 3 sends a signal to pin 28 of

M70.

The air conditioning system is equipped with one recirculation actuator (

N82), two air blending actuators (N78 and N79) and two air districution actuators (N81 and N83).

Recirculation actuator

N82 is controlled by control unit M70, via pins 1, 2, 3 and 4.

Mixing actuators

N78 and N79 are controlled from control unit M70 via pins 5, 6, 7, 8 and 11, 12, 13 14 respectively.

Distribution actuator

N80 is controlled from control unit M70 from pins 15, 16, 17 and 18.

An electronic governer

M72 controls fan N85 at different speeds via an earth command: this is ignition-operated (INT/A) from a line protected by fuse F31 of underfacia control unit B2. It receives a control signal from pin 33 of the control unit and returns a feedback signal to pin 9 of M70.

Fan

N85 is supplied directly by maxifuse A/C of B5.

Pin 36 of

M70 controls activation of the compressor.

The outdoor temperature sensor is located on door mirror

P60: the sensor is connected to the control unit on door H44 and thence, via the CAN network, to M70.

Pins 34 and 35 of control unit M70 connect to Body Computer M1 and node H44 via the CAN line: speedometer signal, windscreen washer signal for activation of recirculation, window and sunroof shut command, battery voltage signal, heated rear window on signal.

See E6021 COMPRESSOR ENGAGEMENT

Parts & tools for this job For 2003 Alfa Romeo GT

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