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Makes 🢒 Oldsmobile 🢒 1998 🢒 LSS 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Control Assembly Description

Control Assembly Description C61 Oldsmobile


Object Number: 330539 Size: SF

The heater and A/C control is the vehicle operator's control point for the manual air conditioning system. The heater and A/C control includes the following components:

    • A rotary knob which selects the system operating modes. The following items are the system operating modes:
       - OFF
       - MAX A/C
       - NORM A/C
       - BI-LEVEL
       - VENT
       - HEATER
       - DEFOG
       - DEFROST
    • A temperature control
    • A fan speed rotary knob
    • A rear defogger switch

Mode Selector Knob

The rotary mode selector knob on the heater and A/C control assembly controls the following components:

    • The 2 electrical switches
    • The vacuum valve

The electrical switches activate the following components:

    • The blower
    • The A/C compressor

The vacuum valve supplies or vents the vacuum to the vacuum actuators. The vacuum actuators determine the following conditions:

    • The air intake
    • The discharge locations

By supplying vacuum to the actuators in various combinations, the vacuum valve controls whether the air comes out of the following parts:

    • The floor outlets
    • The panel outlets
    • The defroster outlets

The vacuum valve also controls the following:

    • Whether fresh (outside) air draws into the system
    • Whether inside air recirculates

Temperature Control Knob

The rotary temperature control knob is a potentiometer which sends a voltage signal to the A/C temperature valve actuator. The voltage signal varies according to the temperature knob position.

When the temperature control knob moves fully to the left (COOL), less than 1 volt is supplied to the A/C temperature valve actuator.

When the knob moves fully to the right (WARM), the battery voltage is supplied to the A/C temperature valve actuator.

Fan Speed Control Knob

The fan speed control knob actuates the fan speed switch inside the heater and A/C control. The fan switch position determines whether current flows to the following components:

    • The blower resistor assembly
    • The blower relay

With the mode selector knob in any position but OFF, the following actions occur:

    • The fan circuit activates.
    • The fan operates at the speed selected.

Control Assembly Description C67 Buick


Object Number: 330561 Size: SF

The electronic heater and A/C control assembly is the vehicle operator's control point for the electronic air conditioning system. The heater and A/C control includes the following components:

    • Soft-touch buttons for the following system operating modes:
       - OFF
       - MAX A/C
       - NORM A/C
       - BI-LEVEL
       - VENT
       - HEATER
       - DEFOG
       - DEFROST
       - RECIRC
       - UPPER
       - LOWER
    • A blower speed control
    • A temperature control lever
    • The ON/OFF switch located in the heater and A/C control for vehicles equipped with a rear window defogger

Operating mode buttons contain an LED indicator that illuminates when selected. The rear window defogger button also contains an LED indicator.

The heater and A/C control is the electronic air conditioning systems control center. The heater and A/C control sends commands to the system components that control the following functions:

    • A/C compressor operation
    • Air discharge location
    • Air discharge temperature
    • Air discharge blower operation

Control Assembly Description C61 Pontiac


Object Number: 330555 Size: SF

The heater and A/C control is the vehicle operator's control point for the manual air conditioning system. The heater and A/C control includes the following components:

    • A rotary knob which selects the system operating modes. The following items are the system operating modes:
       - OFF
       - MAX A/C
       - NORM A/C
       - BI-LEVEL
       - VENT
       - HEATER
       - DEFOG
       - DEFROST
    • A temperature control
    • A fan speed rotary knob
    • A rear defogger switch

Mode Selector Knob

The rotary mode selector knob on the heater and A/C control assembly controls the following components:

    • The 2 electrical switches
    • The vacuum valve

The electrical switches activate the following components:

    • The blower
    • The A/C compressor

The vacuum valve supplies or vents the vacuum to the vacuum actuators. The vacuum actuators determine the following conditions:

    • The air intake
    • The discharge locations

By supplying vacuum to the actuators in various combinations, the vacuum valve controls whether the air comes out of the following parts:

    • The floor outlets
    • The panel outlets
    • The defroster outlets

The vacuum valve also controls the following:

    • Whether fresh (outside) air draws into the system
    • Whether inside air recirculates

Temperature Control Knob

The rotary temperature control knob is a potentiometer which sends a voltage signal to the A/C temperature valve actuator. The voltage signal varies according to the temperature knob position.

When the temperature control knob moves fully to the left (COOL), less than 1 volt is supplied to the A/C temperature valve actuator.

When the knob moves fully to the right (WARM), battery voltage is supplied to the A/C temperature valve actuator.

Fan Speed Control Knob

The fan speed control knob actuates the fan speed switch inside the heater and A/C control. The fan switch position determines whether current flows to the following components:

    • The blower resistor assembly
    • The blower relay

With the mode selector knob in any position but OFF, the following actions occur:

    • The fan circuit activates.
    • The fan operates at the speed selected.