Coolant Temperature Sensor / Switch HVAC: Testing and Inspection

TESTING CABIN TEMPERATURE SENSOR/SWITCH

1. Remove thermo switch as outlined in Service and Repair.
2. Connect suitable ohmmeter across switch terminals, then immerse lower part of switch in water.
3. Place thermometer in water and heat. When water temperature reaches approximately 221°F, switch contacts should close and the ohmmeter should indicate continuity.
4. If switch does not operate as indicated, replace.