Heating & Air Conditioning Description; Operation - DaimlerChrysler SPRINTER2006 Service Manual

24 - 2 HEATING & AIR CONDITIONING
Fig. 2 Heater Housing
1 - SCREW (12)
2 - UPPER HOUSING
3 - A/C EVAPORATOR
4 - EVAPORATOR O-RING SEAL (2)
5 - EVAPORATOR GASKET
6 - VENTILATION HOUSING GASKET
7 - LOWER HOUSING
8 - WIRING HARNESS
9 - BOLT (3)
10 - HEATER CORE
11 - HEATER CORE TUBE ASSEMBLY
12 - HEATER CORE TUBE GASKET
13 - HEATER CORE TUBE O-RING SEAL (2)
Some vehicles are equipped with an additional
Denso 10S17 A/C compressor mounted to the engine
which is used for the optional rear A/C system and
various add-on A/C systems (Fig. 3).
Fig. 3 Denso 10S17 A/C Compressor
A heater booster is used to aid in warming the
engine coolant. The heater booster system can be
switched on while the vehicle is being driven to help
the engine reach its normal operating temperature
quickly and will help aid in heating up the air within
the passenger compartment quickly when requested
by the operator (Fig. 4).
Fig. 4 Heater Booster

OPERATION

Outside air enters the vehicle through the hood
opening at the base of the windshield, and passes
through the ventilation housing located in the engine
compartment into the heater housing located behind
the instrument panel. Air flow velocity is adjusted
with the blower motor speed selector thumbwheel on
the A/C-heater control. The air intake openings must
be kept free of snow, ice, leaves, and other obstruc-
tions for the HVAC system to receive a sufficient vol-
ume of outside air.
The automatic temperature control (ATC) system
controls interior temperature by taking actual values
from the temperature sensors and the CAN bus and
comparing them to the nominal value of the temper-
ature control switch. The electric pulsed heater valve
is then energized depending on the requested quan-
tity of heat and an electrically-operated water pump
gives a nearly constant water flow for exact temper-
ature regulation. If the solenoid is not energized, the
coolant circuit to the heat exchanger is fully open. To
control the temperature the solenoid valve is pulsed
by the ATC in periods of four seconds.
The mode control knob on the A/C-heater control is
used to direct the conditioned air flow to the selected
air outlets. The mode control knob operates the mode
doors by cables connected to the mode doors.
VA