Owner`s manual
OPERATION — PAGE 12
WILLIS POWER SYSTEMS
SPECIAL INSTRUCTIONS FOR UNIT TYPE
Closed Loop System for A/C only
C F Hose Fittings Direction of Coolant
Flow
Hoses pictured above do not show the proper installation, and is provided solely
as an overview of connections. Refer to your installation manual for specic
instructions or contact WPS.
• The small fan only turns on when the AC is engaged to pull the
heat out of the chassis that is produced by the engine and the
AC compressor.
• The condenser’s cooling fan should run anytime the APU is on.
• This unit alone supplies no heat whatsoever.
• The APU is designed to automatically monitor and charge the
truck batteries with 150 AMP alternator.
• Leave the thermostat on AC, and set the temperature.
• Because the coolant is self contained, always change coolant
yearly with 50/50 coolant premix. Remember to use the proper
coolant to water ratio to prevent damage to your unit in cold
temperatures.