1999 Other Mazda Models blower motor

Hi
Started my Mazda B2500 pick-up this morning after a truck was outside all winter. Tried the AC and got a growling and squealing sound. Also looked like blue vapors coming out of vents.
Under the hood found a squirrel nest with many acorns near the firewall passaenger's side.

Fuses and reayys all ok

Can you tell me where the motor blower is located?Inside or outside the cab? Is it much effort to replace?

Thanks, Don





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