FixVault

1969 Vacuum System Component Functions

VACUUM RELAY VALVE CHECK
Control Head Setting Tester Settings Tester Should Indicate: If not, check the following: Electrical Diagram Probe Points: Voltmeter should read
Function Manual Control Voltage
Hi Front Manual Max. Cold Transducer With large vacuum hose from transducer connected to tester and open end of hose (green) removed from transducer closed off, vacuum gauge should indicate no vacuum. If vacuum is indicated, vacuum relay valve is defective.
VACUUM FUNCTION CHECKS
Hi Front Manual Max. Heat Trans. Hi Blower Outside air (air door closed to car body). Hot air from heater outlets. Defective Power Servo; Leak in Vacuum System; Temp.; Door Link Disconnected or Jammed; Defective Vacuum Relay Valve
Max. Cold Hi Blower Recirc. Air (air door open to car body) cold air from A/C outlets. Defective Mode Door Diaphragm
Component Vacuum Applied No Vacuum Applied
Inside Air Door Diaphragm (Pink Hose) Air Door Open to Recirculated Air (Car Body) Air Door In Mid Position
50% Recir. Air
50% Outside Air
Outside Air Door Diaphragm (Purple Hose) Air Door Open to Outside Air (Closed to Car Body)
Power Servo Maximum Heat Maximum Cooling
Vacuum Relay Valve Vacuum Applied to One Port Side Opens a Passage Through the Valve to Allow Transducer Vacuum to be Supplied to the Power Servo No Vacuum Applied Closes Vacuum Supply to Power Servo
Water Valve No Water Flow Through the Heater Core Water Flow Through the Heater Core
Mode Door Diaphragm Vacuum to Linkage Side Vacuum to Covered Side Airflow Out of Upper and Lower Outlets. Door Open 1" From 100% Lower Outlet Position
Airflow Out Heater Ducts Airflow Out of Upper Ducts
Defroster Diaphragm Full Airflow Out Heater Outlet Full Airflow Out Defroster Outlets (Full De-Ice) Airflow Divided 1/3 Out Defroster Outlets, 2/3 Out Heater Outlets
Transducer Zero Voltage Applied to Transducer Results in Maximum Vacuum Supply 10 Volts Applied to Transducer Results in No Vacuum Supply