The AC in my 2007 BMW 335i stopped working “all of a sudden”, what’s the problem?
What Happened?
One afternoon, I was driving in my well cooled car, enjoying the fact that the temperature in my car was well below of the temperature outside the car. Cold air was flowing, music was blaring, and I was enjoying a nice country drive. Later in the day, I jumped into the car, turned the AC to max….but nothing happened, no air and no fan noise!
Is it the Fuse?
I was hoping the problem was a blown fuse. For my 2007 BMW 335i, I have both the owners manual and the fuse legend behind the glove box. In my car, the blower motor is dependent upon fuse #67.
The fuse checked out ok….its probably the blower motor but I’m still going to make sure the motor is getting the power it needs.
Check the Power!
To make sure the motor is getting the power it needs, I found my multimeter, and followed the process detailed on this post at wheelsjoint.com
- Remove the electrical connector from the blower motor
- Insert the multimeter probes into the connector (as shown in the image below)
- Turn on the AC (I turned it to Max)
- Check the voltage, it should read around 12 volts. If it does, the problem is likely the blower motor itself.
Removing the AC Blower Motor
I don’t need to rehash the entire removal process, but this 43 second video is pretty good: https://www.youtube.com/watch?v=jCQodjHc5_o
I will say this, the T20 screws removed at the beginning are the only bolts you’ll need to remove. After removing those 2 bolts, you should be able to rotate the AC blower motor and pull it out.
I made the mistake of removing the three bolts shown below but you don’t have to remove them to remove the AC blower motor.
When I pulled the motor out, some leafy type debris came with it. I made sure I could move the fan manually and tried to clean it up. I found some Mass Airflow Sensor cleaner that said, “safe for delicate wire and plastic” and thought, “Why not?” (Let me know in the comments if this was a terrible idea….)
I decided to connect the motor back up to see what would happen and to my surprise, it started right up. I put everything back together, expecting the motor to stop working after doing so, but it continued to run, and I have enjoyed the cold AC it provides.
However….
After reinstalling the motor, I drove the car a few times without turning on any audio and noticed that there are times when the blower motor sounds like a small flock of birds. I bet the motor has been doing this for some time but that music may have masked the sound. I’m glad the motor is working but I think I just bought myself a little time before a new blower motor is needed.
If your AC stops working all of a sudden, remember….”check the fuse, check the volts, check the motor”….and turn the music down. 🙂