WD Catalog 2018

816 / 1003

Introduction
This manual has been designed and written for your use. Take your time
reading it. Study the illustrations, charts and photos. Figure 1 shows a typical
HVAC system (heating, ventilating, air conditioning) installed.
The illustration is cut away so you can see component locations. All of the
main components are labeled, connected together and positioned approxi-
mately as they appear in the vehicle. These components may differ from one
cab to another. There could be other system devices for safety or perhaps
sleeper cab comfort.
BLOWER AND
MOTOR
EVAPORATOR
COIL
HEATER CORE
EXPANSION
VALVE (TXV)
COOLANT
LINE (RETURN)
SIGHT GLASS
BINARY™
OR TRINARY™
SWITCH
RECEIVER-
DRIER
REFRIGERANT
LIQUID LINES
WATER PUMP
FAN CLUTCH
RADIATOR MOUNTED
CONDENSER
OR GRILLDENSER
REFRIGERANT
SUCTION LINE
REFRIGERANT
DISCHARGE LINE
COMPRESSOR
MAGNETIC
CLUTCH
AC/HEATER
VENTS
COOLANT
(WATER) VALVE
COOLANT LINE
SUPPLY
DEFROSTER DUCT
Figure 1
The illustration shows a
typical HVAC system with
in-cab components mounted
on the fire wall. The main
system components are
noted in this illustration.
Intro-1