Mode Control Switch

MODE CONTROL SWITCH
1. Connect the vacuum tester to black color hose of the vacuum connector.
2. Connect the vacuum hoses to mode control-switch.
3. Clog the vacuum port for fresh/recircle control switch.
4. Check for vacuum hiss from the mode switch and vacuum hoses, and inspect for air flow between each hoses when the mode switch is a the each positions as shown.
If air flow is not as specified, replace the mode switch.