When I turn on the heater or A/C(either by pushing "Auto" or regulating the fan speed manually), I hear some chirpping sound (almost like birds chirpping) coming from under the dash. This sound is in addition to the regular blowing sound coming from the heater. It doesn't matter how high the fan is set, the sound is pretty much the same and it goes away once the heater/A/C is turned off. So I think it is pretty much coming from the fan. Except for this weird sound, my A/C and heater work fine.
First, what is that fan called? Is that the blower motor? Second, is it really my problem? Can I get to it somehow and may be clean the blades (if any) or something?