[Terry Harapiak]

Hello All; I have recently acquired a 2004 Silhouette GLS van with all the bells and whistles that was driven since new by a couple who gave up driving. It has just under 100,000 miles but the airflow out of the front heater on any of the settings is very poor even though the blower motor is at top speed. There are no obvious restrictions, the cabin air filters are clean, but the switch on the center console that changes the air intake from external to internal is stuck on "external" and will not change even when the button is pushed.
Suggestions, please, and thanks in advance for any and all help.

 

[RayVoy]

That's normal. You need the AC on, and the selector in the dash position before the recycle position can be selected.

 

[Pikey]

Is the fan speed changing when you select different speeds with the dial? Also, is the air blowing just out of the dash vents or can you feel air blowing from the defrost or floor vents while it is on just the dash setting ? If the sped is not changing then you might have a resistor issue. If you feel air blowing out of places other than the dash vents then you might have a problem with an actuator. You can pull the hvac fuse, leave it out for s minute. Then put it in, turn the key on, then turn the hvac on. Then don't touch anything. This might recalibrate the actuator

 

[Terry Harapiak]

Thanks for the replies. The blower fan changes according to the settings and where the air comes out changes according to the settings, but no matter where the air comes out, it is feeble. I will try the HVAC fuse as you suggest.

 

[Terry Harapiak]

Hello Again; I pulled the HVAC fuse as per suggestions, and it made no difference. However, I watched the airflow carefully while my wife switched from heat to dash vents to defrost and while I had thought switching made a difference, it seems that it does not-there is a bit of airflow out of all vents but does not change no matter what the setting. Can anyone tell me what might be wrong?

 

[RayVoy]

There is a door(s) inside that is suppose to move every time you change position of the switch (it is called a mode door and the switch is the mode switch).
The mode door is moved by a small motor, called the mode actuator. Usually these motors fail. However, there could be something jamming the door.
Sometimes, the actuator just gets out of synic. Sometimes, it can be re-syniced by disconnecting, then reconnecting the battery (use the neg post and cable). Sometimes it takes move than one try to resynic,

 

[Terry Harapiak]

Thanks for the prompt reply. Would this motor failing cause the airflow to be dissipated out of all the vents more or less equally?

 

[RayVoy]

It would depend upon where the door was/is when it stopped moving.

 

[Terry Harapiak]

Thanks. The only other possibility I could come up with was that the evaporator coil had gotten bunged up and I would have to pull the whole dash apart and replace the coil. It may yet come to that but this sounds a lot less dire.

 

[RayVoy]

The evap is where the air flow gets cold, the heater core is where the air flow gets heat.
The air directed past these unit by the position of the blend door. This door also has an actuator, but it is not the reason the air flow does not move from floor to vent to defrost.