General Information

DESCRIPTION
The unit housing is divided into two sides. The left side is called the air distribution module. The air distribution module is the same on vehicles with or without air conditioning. On the right side there is either a blower module (non-A/C vehicles) or an evaporator/blower module (vehicles with A/C). The blower module is unique to heater only systems.

Heater Only Unit Housing:

The air distribution module contains the heater core and doors used to control air flow. The vehicle uses the same air distribution module on all models (with or without air conditioning).

A/C Heater Unit Housing:

The air conditioning evaporator is located in the evaporator/blower module. To service the heater core, evaporator and/or any of the air doors the unit housing must be removed from the vehicle.

NOTE: This information covers both Left-Hand Drive (LHD) and Right-Hand Drive (RHD) versions of this model. Whenever required and feasible, the RHD versions of affected vehicle components have been constructed as mirror-images of the LHD versions. While most of the illustrations used represent only the LHD version, the diagnostic and service procedures outlined can generally be applied to either version. Exceptions to this rule have been clearly identified as LHD, RHD, or Export if a special illustration or procedure is required.

OPERATION
The A/C-Heater System is powered by several fuses. Fuse 10, a 15 Amp fuse located in the fuse block, is HOT in the RUN position. This fuse powers the coil side of the radiator fan, and A/C compressor clutch relays located in the Power Distribution Center (PDC).

A 30 Amp maxi fuse, on circuit A16 located in the PDC, powers the contact side of the radiator fan relay. This fuse is HOT at all times. The 10 Amp micro fuse, on circuit A17 located in the PDC, powers the contact side of the A/C compressor clutch relay

The A/C-Heater blower motor is protected by a 25 Amp fuse located in cavity 7 of the fuse block. This fuse is HOT in the RUN position only. When the ignition switch is in the RUN position, power is supplied to the fuse on circuit A22. The power leaves the fuse on circuit C1, and goes directly to the blower motor.

A 4 Amp fuse, located in cavity 12 of the fuse block, is used to illuminate lamps in the A/C-Heater control. The fuse is HOT at all times.