Cabin Temperature Sensor / Switch: Testing and Inspection

When there is an open in the sensor circuit, the system will operate at maximum heating, and when there is a short in the circuit, the system will operate at maximum cooling. To check sensor circuit, proceed as follows:
1. Make sure that air is being drawn through the in-car sensor when the system is operating.
2. Check resistance of sensors. The in-car sensor should have a resistance of 620-1700 ohms. The ambient sensor should have a resistance of 620-1700 ohms.
3. If sensor values are not as specified, replace affected sensor.
4. Check resistance of solar sensor, if equipped. If no continuity exists, replace pressure switch.