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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Vacuum Sensor / Switch HVAC: Testing and Inspection

Servo Control Unit:





VACUUM SWITCH (Inner) SERVO CONTROL UNIT

Testing: In full cooling mode check vacuum supply to water valve.

If none available, check at (inner) vacuum switch on camshaft. Supply pipe color code = White - Red pipe to water valve.

VACUUM SWITCH (Outer) SERVO CONTROL UNIT

Testing: In full cooling mode check vacuum supply to (outer) switch on camshaft. Bypass switch and observe that center dash flap opens. Supply pipe color = White - Pipe to center dash flap = Black.