I recently bought an 01 Oldsmobile Alero. The heater vent fan works, but only on the two highest settings, which is not a big problem. However, I just noticed that the knob that you turn to go from vent to vent/floor to defroster does not work. I can twist that knob, but the air only comes out of the vents, nothing comes out on the floor or the defrost settings.

What do I need to do to fix this so air will come out on the defrost settings to the windshield this winter? Thank you, Duane.

 

Answer: The problem with the fan speeds is most likely the blower resistor. This is a very common failure. It is located under the passenger side of the dash, between the blower motor and the firewall- The positions not changing on the heater - air conditioning system may be a vacuum problem, control unit faulty, or a mode door actuator. The system uses vacuum into the switch on the control panel, then vacuum is sent to or removed from different actuators in the dash to control the position of the air flow. Normally a lack of vacuum to the system will cause air to only blow out defrost and floor, so that does not sound like the problem. I would suspect the problem is in the control unit.

 

2002 Olds Alero
Engine Size : 2.2L
Question: I loose air flow through all vents after car has been running a little while. the fan still blows but nothing comes out the vents. Any help would be really appreciated.

 

Answer: If the air conditioning / heater fan is still blowing, then the air must be going somewhere. My guess is that it has switched positions and is not coming out of the center vents anymore, but maybe out the defroster or floor. This is an electric HVAC system so you may have a problem with the MODE valve actuator motor. This is what directs the airflow to the different mode positions.

 

Be Social With Us !

Google Bookmarks


Leave your comments

Post comment as a guest

0 / 300 Character restriction
Your text should be in between 10-300 characters

    Comments (2)

      How Things Work

      Engine Coolant System | Water Pump Radiator Thermostat Heater Core

      The cooling system's function is to maintain an efficient engine operating temperature during all engine speeds and operating conditions. The cooling system is designed to remove approximately one-third of the heat produced by the burning of the air-fuel mixture. When the engine is cold, the system cools slowly or not at all. This allows the engine to warm quickly.

      Read more...

      Common Engine Codes

      Electronic Throttle Actuator Control Codes

      P0506 - P0507
      The Electronic Throttle Control (ETC) System uses various inputs from the powertrain control module (PCM). This system uses the inputs to control the idle speed through serial data circuits to the throttle actuator control (TAC) module.

      Read more...