defroster is making a loud noise from the engine every time i turn it on

Sounds like the bearings in the blower motor are shot, or there is something in there -- possibly a mouse nest or broken "Squirrel cage" which is the plastic fan part of the blower motor.

I had a chevy pickup that when the heater motor was cold would squeal like crazy. It was a bad case of dry motor bearings. It can be repaired by removing the fan motor and lubing the bearings. When you remove the fan motor check for foreign matter in the heater box wiggle the squirrel cage side to side checking for worn or damaged bearings. Turn the the motor by hand there should be no tight spots or binding. Good Luck from Electoman!

squirrels love the heater casing there is a simple inspection port just to the side of the blower motor instead of removing your complete dashand interior you might just be able to see if any debris is in there