Bi-Level Mode

WARNING: This page is about a different car, the 2002 Buick Regal and 2002 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.

When the operator selects Bi-Level, the following occurs:

The A/C Bi-level mode actuator is in neutral position.
The heater/defroster actuator has vacuum applied to it through the Red vacuum line.
The heater/defroster actuator closes the defrost door, thus opening the heater door though mechanical linkage.
Vacuum is bled off the mode actuator and the vent door is held stationary in the half open position.