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· 750Li Lover
2009 X5 35d 170k
58 Posts
Discussion Starter · #1 ·

(2009 BMW X5 35D.)

The front blower for both heat and AC is not working at all. It slowly had gotten worse with blowing then quit altogether. Rear heat and blower are working when I check off (Use Front Settings. I'm stumped on diagnosis and parts and there is no recall on this issue. I have researched the solution and came up with four possible parts myself but it may be a combination or something else entirely. Also not sure where to locate some of the items like the heater Heater Relay Switch.

Parts are:
1) Heater Relay Switch. (BMW Part Cost $11.) Problem is I don't know where to find it. Any help here?
2) Blower Motor Resistor/Regulator. Also called FSU Final Stage Unit. (BMW Part Cost $122.)
3) Blower Motor. Blower Motor Fan. Cost $160.
4) Heater Control Valve. Cost $40.

a) Do you know what could possibly be causing this and what parts to try first? I am leaning towards the heater Relay Switch and Blower Motor Resistor/Regulator first.
b) Do you know of any possible solution to this problem?
c) Do you know where to find a good repair manual. I have downloaded 3 now and none of them address the troubleshooting of this.
d) Would a computer scanner work to diagnose? I have a friend/mechanic who is doing the work and he has one but not sure if this will show up as an error code or not.

Any help with diagnosing or repairing would be much appreciated. I will post the solution once I get it repaired. Thank you so much.



· Nuclear engineer
02/2012 X5 35d M57Y CPO 127+K miles NOKIAN WR G4
24,884 Posts
Everything that you need to know is at or

What "quit" and how do you know that it quit?

There is one blower for AC and heat, but blowing has nothing to do with the HCV.

In the knowledge base stickie at the top of the E70 (sub)forum is a link URL to a huge G00gle drive file of BMW technical system descriptions including "E70 Climate Control Systems."
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