CNH T8000 — TABLE OF CONTENTS

T8010/T8020/T8030/T8040 MASTER TABLE OF CONTENTS A/C TROUBLESHOOTING ..............................................................................................SECTION 50, CHAPTER 1 SAFETY PROCEDURES ............................................................................................................................ 50-1-5 SPECIAL TOOLS ........................................................................................................................................ 50-1-6 A/C THERMAL OPERATION ......................................................................................................................

50-1-7 A/C SYSTEM COMPONENTS ................................................................................................................... 50-1-9 Cab HVAC Box Components - Automatic Temperature Control ............................................................... 50-1-9 Chassis Components .............................................................................................................................. 50-1-11 AUTOMATIC TEMPERATURE CONTROL (ATC) OPERATION ............................................................. 50-1-12 Operation Modes .....................................................................................................................................

50-1-15 Automatic Mode .................................................................................................................................... 50-1-15 Defog Mode ........................................................................................................................................... 50-1-15 Automatic Operation Summary ............................................................................................................. 50-1-16 Defog/Dehumidify Operation Summary .................................................................................................

50-1-17 ATC Fault Codes ..................................................................................................................................... 50-1-18 ATC Fault Code 111 .............................................................................................................................. 50-1-18 ATC Fault Code 112 .............................................................................................................................. 50-1-19 ATC Fault Code 115 ..............................................................................................................................

50-1-19 ATC Fault Code 116 .............................................................................................................................. 50-1-20 ATC Fault Code 120 .............................................................................................................................. 50-1-20 ATC Fault Code 121 .............................................................................................................................. 50-1-21 ATC Fault Code 122 ..............................................................................................................................

50-1-21 ATC Fault Code 125 .............................................................................................................................. 50-1-22 ATC Fault Code 126 .............................................................................................................................. 50-1-22 ATC Fault Code 127 .............................................................................................................................. 50-1-23 ATC Fault Code 128 ..............................................................................................................................

50-1-23 ATC Fault Code 129 .............................................................................................................................. 50-1-24 ATC Fault Code 130 .............................................................................................................................. 50-1-24 ATC Fault Code 131 .............................................................................................................................. 50-1-25 ATC Fault Code 132 ..............................................................................................................................

50-1-25 ATC Fault Code 133 .............................................................................................................................. 50-1-26 ATC Fault Code 134 .............................................................................................................................. 50-1-26 Locating System Problems Without Fault Codes ...................................................................................... 50-1-27 Controller-Based Resistance Tests .........................................................................................................

50-1-27 ATC Controller Test (Connector J8 Test Points) ...................................................................................... 50-1-29 ATC Field Reported Symptoms/Causes ................................................................................................... 50-1-32 Compressor And Clutch ............................................................................................................................ 50-1-33 Operational Check ..................................................................................................................................

50-1-33 Electrical Test .......................................................................................................................................... 50-1-36 Compressor Clutch Control Circuit Test Procedure ................................................................................ 50-1-36 Service Note: Adjusting Clutch Air Gap .................................................................................................. 50-1-38 High And Low Pressure Switch Clutch Latching Circuit ............................................................................

50-1-39 Background ............................................................................................................................................. 50-1-39 Possible Failure Modes - Fault Codes 129 and 134 ............................................................................... 50-1-40 Electrical Test .......................................................................................................................................... 50-1-41 High Pressure Switch and Circuit Test ....................................................................................................

50-1-41 Low Pressure Switch and Circuit Test .................................................................................................... 50-1-42 Heater Control Valve ................................................................................................................................. 50-1-43 Operational Check .................................................................................................................................. 50-1-43 Electrical Test ..........................................................................................................................................

50-1-44 Heater Control Valve Power, Signal and Ground Test ............................................................................ 50-1-44 Blower Speed And Temperature Control Potentiometers ......................................................................... 50-1-45 Background ............................................................................................................................................. 50-1-45 Possible Failure Modes - Fault Codes 120, 121 .....................................................................................

50-1-45 Electrical Test .......................................................................................................................................... 50-1-46 Common Control Potentiometer and Circuit Test Procedure .................................................................. 50-1-46 9