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

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

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Blower Controls

The Blower Motor is a variable speed motor. The higher the voltage applied to the motor, the faster the speed.

Battery voltage to the Blower Motor is supplied by the heater and A/C Controller by way of the Blower Motor Relay. At LOW and MEDIUM speeds, the voltage is stepped down by the Blower Motor Resistors. At HIGH speed, the Blower Motor Relay is energized, removing the Blower Motor Resistor from the circuit. Battery voltage is then applied directly to the Blower Motor through the Blower Motor Relay. The motor will then run at maximum speed.