Climate-Control system problem

There’s a problem with my climate-control system. When I turn the fan on, there is no air blowing through the outlets on the instrument-panel. (There is air blowing thru the 2 vents immediately above the floor, and some air blowing at the base of the windshield). This problem exists regardless of what speed I turn the fan on, and regardless of which climate-control setting I choose (or whether I turn on the A/C).

This problem WAS occurring on an intermittent basis, and seemed to develop in RESPONSE TO my turning the knob to “defrost.” Now, however, the problem seems to be permanent. I wonder whether the basic problem is with the round knob that controls the various climate-control settings, as this knob seems somewhat hard to turn.

I have a 2004 Buick Century sedan, with automatic transmission (4speed) w/overdrive, V-6 engine 3.1 L.

If the mode knob is hard to turn, then more than likely the problem is with the vent control module.


If it doesn’t turn out to be the module, could be one or more of the vent door actuators are stuck. Some cars use vacuum to power these, others use electrical stepper motors. I’ve heard reports that the stepper motor versions are particularly unreliable. You might do a little research, see which your car uses. (The most reliable vent door mechanisms use early 20th century technology, cables.)

Well, I’ve now found out that the problem was with the knob on the climate-control module. A new knob has fixed the problem Thanks for all the input!!

Happy to hear it turned out to be a simple fix. Thanks for posting the results.