Liquid Cooling System Service . . . . . . . . . . . . . . . .327 Changing Coolant and Flushing the Cooling System | Belt and Hose Replacement | Th ermostat Replacement | Cooling Fan Replacement | Coolant Pump Replacement | Radiator Replacement Air Cooling System Service . . . . . . . . . . . . . . . . . . .333 Cleaning Fins on an Air-Cooled Engine | Replacing Blower Belt | Replacing Blower and Bearing | Replacing Th ermostat Chapter 21 Air Delivery and Manual HVAC Control Service . . . . . . . . . . . . . . . . . . . . . 337 Air Delivery and Manual Control System Problems . . . . . . . . . . . . . . . . . . . . . . . . . .338 Blower Motors and Related Parts | Cabin Filter/Air Intake Filter | Ducts and Air Doors | Manual Control Panels Air Delivery and Control System Service . . . . . . . . .342 Blend Door Cable Adjustments | Removal and Replacement of Components | Checking Aft erblow Modules Chapter 22 Automatic Temperature Control System Service . . . . . . . . . . . . . . . . . . . . 353 Automatic Temperature Control System Problems. . .354 Electronic Temperature Control Systems | Electronic Control System Self-Diagnosis Electronic Temperature Control System Testing. . . . .358 Testing Input Sensors | Testing Output Devices | Mechanical Temperature Control Systems | Electromechanical Temperature Control Systems Electronic Temperature Control System Service . . . .360 Computer Reprogramming | Control Head | Temperature Control Computer | Air Temperature and Sunload Sensors | Replacing Output Devices Mechanical and Electromechanical System Service . . . . . . . . . . . . . . . . . . . . . . . . . . . .364 Adjusting Transducer Cables | Replacing System Parts | Power Servo | Amplifi ers Chapter 23 Air Conditioning System Installation and Retrofi tting. . . . . . . . . . . . . . . . . 367 Aftermarket Air Conditioners . . . . . . . . . . . . . . . . . .368 Aft ermarket Air Conditioning Kits | Aft ermarket Air Conditioning Considerations | Installing an Aft ermarket Air Conditioner R-12 to R-134a Retrofi tting . . . . . . . . . . . . . . . . . . .375 Whether to Retrofi t | Level of Retrofi t | Performing a Complete Retrofi t Chapter 24 ASE Certifi cation . . . . . . . . . . . . . . . . . . . . . . . . . 383 ASE Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .384 Other ASE Activities | ASE Test Windows Applying for the ASE Tests . . . . . . . . . . . . . . . . . . . .385 Taking the ASE Tests . . . . . . . . . . . . . . . . . . . . . . . .385 Types of ASE Test Questions. . . . . . . . . . . . . . . . . . .387 One-Part Questions | Two-Part Questions | Negative Questions | Incomplete Sentence Questions Test Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .388 Technician Confi dentiality . . . . . . . . . . . . . . . . . . . .388 Recertifi cation Tests. . . . . . . . . . . . . . . . . . . . . . . . .388 Certifi cation in Refrigerant Recovery and Recycling . . . . . . . . . . . . . . . . . . . . .388 Chapter 25 Career Preparation . . . . . . . . . . . . . . . . . . . . . . . 393 Automotive Servicing . . . . . . . . . . . . . . . . . . . . . . .394 Levels of Automotive Service Positions. . . . . . . . . . .394 Helpers | Apprentices | Certifi ed Technicians Types of Auto Service Facilities . . . . . . . . . . . . . . . .395 New Vehicle Dealers | Chain and Department Store Auto Service Centers | Tire, Muffl er, and Other Specialty Shops | Independent Repair Shops | Fleet Agencies | Government Agencies | Self-Employment Other Opportunities in the Auto Service Industry . . .398 Shop Supervisor or Service Manager | Salesperson or Service Advisor | Parts Person Getting a Job . . . . . . . . . . . . . . . . . . . . . . . . . . . . .399 Finding Job Openings | Applying for the Job Appendix A Rear Window and Mirror Defrosters . . . . . . . . . . 403 Defroster Components and Operation . . . . . . . . . . .404 Rear Window Defroster and Mirror Heating Systems | Control Switch | Defroster Relay | Defroster Operation | Older Rear Window Defoggers Defroster Diagnosis. . . . . . . . . . . . . . . . . . . . . . . . .405 Defroster Service . . . . . . . . . . . . . . . . . . . . . . . . . .406 Replacing Switches and Relays | Repairing the Window Grid Useful Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . 411 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 10 Auto Heating and Air Conditioning