

Components - COMPRESSOR ENGAGEMENT - Fiat DOBLO 1.3 JTD 16V Fino a 10/2000
Component code | Description | Reference to the assembly |
B001 | JUNCTION UNIT | |
C10 | LEFT FRONT EARTH | |
D004 | FRONT/ENGINE COUPLING | |
D29 | ENGINE CABLES/ENGINE SERVICES CABLE COUPLING | |
K10 | FOUR STAGE PRESSURE SWITCH | |
L20 | AIR CONDITIONING COMPRESSOR ENGAGEMENT SOLENOID | |
M010 | ENGINE MANAGEMENT ECU |
Component code | Description | Reference to the assembly |
B001 | JUNCTION UNIT | |
C10 | LEFT FRONT EARTH | |
D004 | FRONT/ENGINE COUPLING | |
D29 | ENGINE CABLES/ENGINE SERVICES CABLE COUPLING | |
K10 | FOUR STAGE PRESSURE SWITCH | |
L20 | AIR CONDITIONING COMPRESSOR ENGAGEMENT SOLENOID | |
M010 | ENGINE MANAGEMENT ECU |
The compressor activation button is built into the knob that selects the fan speed.The above button enables operation of the air cooling circuit, but actual compressor activation is also dependent upon activation of:- the four-stage pressure switch located on the coolant circuit that locks air conditioner activation if coolant pressure is too low or high;- the engine control unit that excludes compressor operation in accordance with engine management mode; e.g. in the case of high engine temperatures or high engine load (sudden acceleration);Enablement of the vehicle interior fan adjustment knob (at least in position 1) and the demister thermostat is also required.The compressor supply circuit is controlled by a special relay located in the engine bay junction unit. The relay supply line is protected by a special fuse.
The compressor activation circuit is controlled by relay R5, contained in engine bay junction unit B01. This is supplied directly by a line from the battery that enters at pin 1 of control unit connector A of the control unit and is protected by fuse F19.The coil of relay R5 is supplied by a signal from relay R9 that in turn receives a direct supply from the battery at pin 1 connector A.Relays R9 and R5 are excited by an earth signal from engine management unit M10 respectively from pins 80 and 79 of connector A.In this way, control unit M10 controls the activation of air conditioner compressor L20 via relay R5.Engine compartment control unit M10 receives signals from 4 level pressure switch K10 to turn on the radiator fan:- operation at first speed from pin 27;- operation at second speed from pin 26;- air conditioner activation from pin 28.