Heater blower motor
#3
MBWorld Fanatic!
If you can find a "pull-a-part" yard within a reasonable distance, it is easy to pull the blower motor and regulator, and the pair will usually be much cheaper than an aftermarket motor.
#5
MBWorld Fanatic!
Most yards will not let you carry an auto battery into the yard. If you have a battery-powered drill or impact tool, you might be able to rig a small set of power connections from the battery to a set of alligator clips. Virtually every yard will mark the parts when you buy them, and will refund your money if the part is faulty.