2001 nissan maxima air condition fan not working

No, a P0449 could never cause a "no crank" condition.

does the blower work in heating if not you have a bad fan

Most likely the blower motor resistor has burned out. It is pretty easy to replace - search online for instructions.

check coolant level in radiator. also check the cooling fans and make sure they are coming on when the car is hot. the a/c will not come on if the car is running hot. the computer will not turn the a/c pump on to keep engine cooler and prevent a brake down. make sure all those things are in working order.

blower moter.... all speeds ????? auto a/c or manual????turn the blower on and rap on it. if it starts working , it will need to be replaced. its located behind and under the glove box.

Your blower motor resistor needs to be replaced. when they go bad, for some reason the fan will only work on high. Replace that resistor and you will be good to go. Let me know if you have any further questions. Thanks for using FixYa!

You will need R134a, and a filler hose. Charge the system on the low pressure side, it should have a blue cap on the charge point.
Your filler hose will only fit the low pressure side, just in case the cap has been removed.

this maybe the motor on the fan or the bearings in the fan wearing out or the bearings in the a/c clutch

Check all fuses in box and in engine bay. Then check relays and grounds.

try here
manual

or here
forum with loads of info