Electronic Climate Control
Electronic Climate ControlControl Panel:
Climate Control System
The climate control system is refined to improve operation and include new functions. The new control panel integrates the control for the optional heated windshield. Revisions to the vents and duct work are described in the Body section of this publication.
Control panel
The control panel style reflects ergonomic design considerations. The lighting of the panel and the function controls have been upgraded to ensure easy identification under all ambient light conditions.
Blower control
The blower control operates the blowers as in the previous systems; however, the MED setting now has a higher air flow.
Heated windshield control
The control switch for the optional heated windshield is included on the control panel. If DEFROST is selected, the heated windshield circuit is activated automatically to accelerate clearing of the windshield. When activated manually, the heated windshield circuit will switch off after 6/2 minutes, unless it is switched off manually.
Demist control
The demist control operates the defrost function exactly as in previous systems.
Recirculation control
This control eliminates outside air intake and should be used only to temporarily exclude undesirable air from entering the vehicle.
Manual control
The manual control overrides the automatic temperature control portion of the system.
Air conditioning control
The previous "humidity" controls are replaced by ON and MAX controls. ON is the automatic control that provides minimum humidity while maintaining automatic temperature and blower control. MAX is a manual control that overrides all other functions except DEFROST and OFF. In MAX, the system provides maximum cooling and the highest blower speed to produce the coldest possible output.
Face level temperature control
Moving the slide control up reduces the temperature of the face level air as compared to the temperature of the footwell air.
Temperature control
The temperature control band is wider than previous systems. In automatic mode, the temperature control selects the desired interior temperature; in manual mode, the temperature control adjusts the vent temperature from full cool to full heat.
Climate control ECU
The climate control ECU is completely new internally, incorporating more durable construction and enhanced components and circuitry. New features are provided as follows:
^ Increase the medium blower speed
^ Extend the temperature range
^ Revise the recirculation switching point
^ Add the MAX air conditioning function
The shape ofthe ECU case is changed to be identical to the XJS climate control ECU case. The ECUs are identified by color: Sedan Range - black, XJS Range - brown.
Climate control unit
In addition to the changes made to the air conditioning portion of the unit, improvements have been made to the vacuum and electrical circuits.
Electrical circuit
The wiring harness uses new connectors to improve reliability. The servo drives have reduced back lash to ensure closer tolerance.
Solenoid Vacuum Pack:
Vacuum harness and solenoid vacuum valve pack
The vacuum harness and vacuum valves are upgraded. The newly designed harness simplifies assembly and improves reliability. The solenoid vacuum valve packcontains the four vacuum valves for operation of recirculation, defrost, coolant valve and center vent.
Coolant Valve:
Engine coolant valve
Control of engine coolant flow to the climate control heater matrix is reintroduced for the 1993 Sedan Range. The new vacuum-operated valve is mounted directly to the engine cylinder head. This valve is a new, more compact design than the previously used in-line valve. The valve is normally open and closes when vacuum is applied.