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

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

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Ambient Temperature Sensor / Switch HVAC: Testing and Inspection

Fig. 4 In-vehicle sensor performance graph (Typical):

Fig. 5 Ambient sensor graph:

Measure resistance of sensor across terminals with unit disconnected from circuit. Sensors which do not fall within 5 percent of specification must be replaced. If sensor is within specification, check continuity of wiring to sensor. If continuity is good, control panel is defective. Note: Letters in Ambient Sensor Graph refer to vehicle series.