The fan dial control has 9 manual settings. I noticed that my fan speed doesn't increase at setting #5 and above. The MAX function doesn't work as well. Heater/AC temperatures seem to be fine; all other climate settings seem to work fine too.

Any ideas? Thanks

Did you look into the microfilter?

Are the microfilters on each side in the engine compartment near the window? I took the driver's side out to check a rattle but put it back in place.

I'm sure somebody mentioned the same problem and the cause was the battery as it would'nt let you go to the higher setting's because of the battery was weak.

I just checked the MAX function again after it warmed up in the garage for some time. It worked this time. This functions seems to be disabled at a predetermined outside temperature (winter). Although the blower did not increase at the level 5-9 setting; only level 1 through 4 make adjustments on the blower speed.

I believe there are 2, one on each side (driver and passenger). I know i need to change mine every now and then it makes noises when i adjust the fan speed to a higher setting.