[aggierandy]

Hi there. I am desperate for help on this one.

I have a 2009 E90 335i with M-Sport about 106k miles. The AC was giving me problems about 3 months ago (fan would not turn on, climate control panel functioned correctly). I figured it was the FSU or the motor so I checked fused to no avail. Then, I disassembled and found the wires in rough shape. I taped them up as best I could and reassembled and things. AC worked OK until about 2 weeks ago.

The same issue popped up so I set aside some time last weekend to replace the FSU. When I got it apart I saw the condition of the wires was bad again so I decided to start there. Following THIS guide, I clipped the wires about 2 inches up, built a new pigtail from a new OEM connector and new terminals. I crimped the new wires in place, hooked up the old FSU and motor, no dice. So I hooked up the new FSU and reinstalled. Nothing. So I went out and got a replacement motor. Nothing. I checked voltage to the FSU and got something like 0.2 or 0.3 V. Definitely not right.

At this point I was at a loss so I took a break. Decided to come back to it and start by checking voltage to the FSU to chassis ground. Immediately ready 12.2 V. Plugged the fan in and it worked. I don't know what changed but we were in business. Until today. I get in the car, no fan.

At this point, even though I had the odd low voltage reading, I figured I had overlooked something and my 10yr old fan motor is probably going out. So I replace it. Nothing.

To summarize, new motor, new FSU, new pigtail.

At this point, I'm at a loss. What's left to replace? Is there a relay somewhere I need to check? Bad IHKA unit? Gremlins?

Its 100F here in Texas and I'm dying. Any suggestions would be greatly appreciated.

[Turbo2Pete]

Are you aware of the blower fan recall on these? (not sure about your model - I've got an '08 335xi that is under recall)

You might be up for a new fan from BMW.

[gbalthrop]

Attached is a pdf containing all relevant recall documents on Blower Final Stage Resistor, the Connector & wiring harness, 17V-676. This shows procedure to be followed in replacing harness, etc. If you have spent money replacing parts yourself, keep receipts & records, and you may be able to get reimbursement.

Here is the TIS circuit diagram for the blower. Of course you can test the motor for function simply by applying 12V+ and ground to the Red and Brown wires that run from the Final Stage to Motor:
https://www.newtis.info/tisv2/a/en/e...bution/ufClUrJ

George

[E90Graphite07]

Mine blew out this past summer; dealer had to replace the harness, which they completed the same morning I dropped off the car. The recall 'fix' is replaced immediately based on a case-by-case basis, and since it was dead hot summer here in TX, and it was just the blower fan not working, but the dash controllers were...they determined both the harness and resistor would be replaced, free of charge.