Vanden Plas L6-4.2L (1982)
Approximately 75% of the air after passing through the evaporator is fed to the dash outlets, the remaining 25% to the footwells.
Vacuum solenoid is de-energized placing inlet flaps in fresh air mode.
Ranco thermostat is conductive and refrigeration cycle operates. Fans are initially on LO speed (always in this mode when Auto is selected).
As camshaft revolves, it trips MED 1 (2nd speed) fan switch then MED 2 (3rd speed).
Center dash flap opens when cam operates outer vacuum switch. Upper and lower heater flaps are closed preventing air passing over heater
cor
Cooling flaps are open - All flaps being operated by camshaft through external linkage.
Water temperature bypass switch activated by camshaft - Water valve closed to prevent water circulation through heater core - Cam closes
vacuum feed from inner vacuum switch. Ranco thermostat overridden by Ranco override switch.
High speed (4th) / Recirculation switch activated by camshaft - Positive voltage via Diode # D3 energizes vacuum solenoid and allows
vacuum feed to inlet flaps placing them in recirculation mode.
Camshaft trips full cooling limit switch inhibiting further camshaft travel.
As selected temperature is reached, the feedback potentiometer, via the amplifier, signals the camshaft to reverse this sequence until
camshaft revolves back to central position.
HIGH & LO FAN SELECTION
In cooling mode, HIGH or LO may be selected either to maintain a high or low air velocity into the vehicle interior; however, all other
functions remain automatic.
INTERMEDIATE SETTINGS
Flap Positions
