Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Ambient Temperature Sensor / Switch HVAC: Testing and Inspection

Ambient Temperature Sensor, A/C

NOTE: Sensor resistance drops with increasing temperature.








Check Sensor
- Use ohmmeter. Carry out measurement at room temperature approx. 2O-23 °C (68-73 °F). Ignition should be switched OFF.
- Resistance: 30 - 40 Ohms.
- If resistance is much higher: 65 - 100 Ohms, replace sensor.