Heating and Air Conditioning - Description

DESCRIPTION

A Manual Temperature Control (MTC) front single zone type heating-A/C system, a MTC front dual zone and rear heating-A/C system and an Automatic Temperature Control (ATC) front dual zone and rear heating-A/C system are available on this vehicle.

To maintain the performance level of the Heating, Ventilation and Air Conditioning (HVAC) system, the engine cooling system must be properly maintained. The use of a bug screen is not recommended. Any obstructions in front of the radiator or A/C condenser will reduce the performance of the A/C and engine cooling systems.

The engine cooling system includes the radiator, thermostat, radiator hoses and the engine coolant pump.

FRONT HEATING AND A/C SYSTEM






NOTE: LHD model shown. RHD model similar.

All vehicles are equipped with a common front HVAC housing (1). The front heating-A/C system combines A/C, heating, and ventilating capabilities in a single housing mounted within the passenger compartment under the instrument panel. The front HVAC housing includes:

- A/C evaporator (2)
- Blend-air door and actuator (3) (dual zone passenger side)
- Recirculation-air door and actuator (4)
- Evaporator temperature sensor (5)
- Blower motor (6)
- Blower motor resistor (MTC) or blower motor power module (ATC) (7)
- Mode-air doors and actuator (8)
- Heater core (9)
- Blend-air door and actuator (10) (single zone or dual zone driver side)

NOTE: An Electric Positive Temperature Coefficient (PTC) heater is used on vehicles when equipped with the 2.8L diesel engine. The PTC heater unit compensates for the lower engine coolant temperatures produced by the diesel engine. The PTC heater unit is mounted in the HVAC air distribution housing, downstream of the heater core.

Based upon the mode selected, conditioned air can exit the front HVAC housing through one or a combination of the three main housing outlets: defrost, panel or floor. The defrost outlets are located on the top of the HVAC housing, the panel outlets are located on the top of the HVAC housing and the floor outlets are located on the bottom of the HVAC housing. Once the conditioned air exits the HVAC housing, it is further directed through molded plastic ducts to the outlets within the vehicle interior. These outlets and their locations are as follows:

- Defroster Outlet - Two large defroster outlets are located near the center of the instrument panel top cover, near the base of the windshield.
- Side Window Demister Outlets - There are two side window demister outlets, one is located in each instrument panel end cap, near the belt line at the A-pillars.
- Panel Outlets - There are four air outlets in the instrument panel, one located near each outboard end of the instrument panel facing the rear of the vehicle and two located in instrument panel center bezel.
- Floor Outlets - There are four floor outlets, one located above each side of the floor panel center tunnel near the dash panel and one behind each front seat.

REAR HEATING AND A/C SYSTEM





The MTC and ATC rear heating-A/C systems are equipped with a common rear heater-A/C housing (1) that combines A/C and heating capabilities into a single unit mounted within the passenger compartment behind the right quarter interior trim panel. The rear heater-A/C housing includes:

- Blower motor resistor (2)
- Blower motor (3)
- Mode door and actuator (4)
- Heater core (5)
- Blend door and actuator (6)
- A/C evaporator (7)
- A/C expansion valve (8)
- Wire harness (9)

Based upon the rear temperature selected, conditioned air can exit the rear heater-A/C housing through one or a combination of the two rear housing outlets: ceiling or floor. The ceiling outlet is located at the top-rear of the housing and the floor outlet is located at the front of the rear housing. Once the conditioned air exits the rear heater-A/C housing, it is further directed through molded plastic ducts to the outlets at the rear of the passenger compartment. These outlets and their locations are as follows:

- Ceiling Outlets - There are four ceiling outlets in the headliner. One located at each outboard side of the intermediate seat position and one located in front of each rear seat position.
- Floor Outlet - There is one floor outlet in the right quarter interior trim panel located behind the right rear door area.