Section 9 --- Electrical Systems - Chassis
The Executive 2005
410
Operating Hints and Tips:
• Air intake and discharge temperatures are greatly affected by ambient temperature and rel-
ative humidity.
• A large amount of cooling capacity is used to dehumidify air as well as cool it. After three
to five minutes of A/C compressor operation, discharged air temperature should be approx-
imately 30º F cooler than the fresh or recirculated air entering the A/C system.
• The air system on the motorhome must have adequate pressure to operate the damper
doors.
• At the beginning of the day, activate the compressor with the engine at idle. This will avoid
sudden high speed activation resulting in damage from lack of internal compressor lubrica-
tion.
• The dash A/C and heater system should be used monthly to keep the compressor lubricat-
ed.
• Warm air will discharge from the dash louvers when the Aqua-Hot is on and the forward
comfort control is set to the FURNACE position. Set the fan control switch between
LOW and HI.
Winter Use:
• De-ice the windshield using the OFF (Defrost) mode.
• Higher temperature discharge air will occur with the blower set to a lower speed setting
until the engine has reached normal operating temperature.
Summer Use:
• Close all windows and vents to hot, humid outside air.
• MAX AC and HI blower will provide a quick cool down.
• Using a lower blower speed will produce cooler discharge air.
A/C Heater:
The A/C system will also produce heat to warm the air in the dash area. Much like the refriger-
ation side of the system, a liquid will be used in the process. This liquid is the engine coolant. The
coolant is passed from the radiator to an electronic water valve. The water valve, when open, will
allow the coolant to flow through the heater core. The heater core is tubing and fins. Air is drawn into
the system by a blower motor through the outside recirculation door opening. Air is blown through the
A/C evaporator core and then through the heater core. When the temperature control is in the WARM
position coolant flows through the heater core. When the temperature is in the COOL position coolant
flow bypasses the heater core. In either position the air flow is felt at the discharge vents.
Diagnosis of Electric Water Valve:
Theory of Operation: The thermostat is a potentiometer. The water valve, which controls the water
flow to the heater core, is opened and closed by a stepper motor mounted on the water valve. A control
module compares the output voltage from the potentiometer to the feedback for the stepper motor of
the water valve. The control module then drives the motor to within one-half volt of the control poten-
tiometer voltage.
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