Ambient Temperature Sensor / Switch HVAC: Testing and Inspection
AMBIENT TEMPERATURE SENSOR TEST1. Turn the ignition OFF.
2. Disconnect and isolate the battery negative cable.
3. Disconnect the ambient temperature sensor harness connector.
4. Measure the resistance of the ambient temperature sensor using the following values:
0 degrees C (32 degrees F) Sensor Resistance = 29.33 - 35.99 Kilohms
10 degrees C (50 degrees F) Sensor Resistance = 17.99 - 21.81 Kilohms
20 degrees C (68 degrees F) Sensor Resistance = 11.37 - 13.61 Kilohms
25 degrees C (77 degrees F) Sensor Resistance = 9.12 - 10.86 Kilohms
30 degrees C (86 degrees F) Sensor Resistance = 7.37 - 8.75 Kilohms
40 degrees C (104 degrees F) Sensor Resistance = 4.90 - 5.75 Kilohms
The sensor resistance should read between these min/max values. If the resistance value is OK, refer to the Wiring Diagrams to test the Signal and Ground circuits. If the resistance values are not OK, replace the Sensor.