2001 BMW 330i..Fan for AC/vent not working?

Can you wiggle the fan front to back when the engine is off? If so, check to see whether it is the water pump or the fan clutch and replace as required....

Replace fan resistor in center console.

there is a voltage regulator in the back of the heater system if you change that it should work again. if i remember right you can get to it via the glove box when it is removed. has heat fins on it.

Sounds like the buttons sticking..

First suggestion, ensure the AC is properly charged... the AC system is very picky... so check belts pulleys and AC charge first... if the AC is healthy and this issue is still present... you have two possible solutions...1. heater control box in dash behind the radio...Expensive part $450+ and lots of labor to pull dash apart... or 2. the heater control valve in the engine bay... $130 part you can do IF you take your time

I'm having the same problem have you fixed yours?

If the blower is the one cutting off iether at AC/heater mode, it could be a faulty fan resistor. To replace it, you have to take off RH side front kick panel, foot air vent and use torx bit.

its not a fuse i had the same problem on my 03 x5 it an ac resistor thats at fault it controls your fan once it goes your fan wont come on or comes on intermitently once again the faulty part is a blower motor resistor should be 100 bucs at dealer or if you shop around i got mine for 75 from local parts store (carquest)

sounds like the resister for the fan is failing. it is located under the dash on the duct work for the blower (fan). you will see two wires going to it. unscrew the bolts or screws that hold it in and replace it with a new one. it should work fine after that.

the final stage resistor on all BMW blower motors controls everything (power and grond ) 99% of blower motor issues is the resistor. not to hard to install either.