DIYbanter - View Single Post - Root cause insight into the common BMW blower motor resistor failures

Tony Hwang

wrote:
On Thursday, November 14, 2013 7:37:33 AM UTC-5, wrote:
I have tried to repair the FSU for BMW e46 by replacing the two MOSFET transistors with equivalent: IRF3205 (and even two more powerful) but it seems they cannot do the job due to other electronic component which i cannot figure out. Even though there is a change on G -gate the transistor won't change the flow ..there must be something on the Base or Collector ... I'm stunned cause i tried repairing two of them

Hi,
Checked/set proper bias voltage for the replacement MOSFET?
If you don't know how or can't do it they won't work properly for sure.

Root cause is BMW designed/specd a piece of crap and
doesn't give a damn about resolving it, even thouh it's
been an obvious problem for a decade, guys like you
have bitched about it and their service people obviously
know about it.

They've achieved some other marvels of engineering, like
putting electronics inside the aux fan that sits in front
of the hot radiator, to vary the fan speed. Simple on/off
fan wasn't good enough. So, they put electronics in an
environment where it gets 130F, salt, water, God knows what.
Of course they fail. And you can't even diagnose it because
no one knows what kind of signal they send it to turn it on,
off, fast, slow, etc. BMW can, with their magic computer that
they can hook up to turn it on and off. So, every 2 years
you buy a new one for $275 aftermarket price, plus labor.
Go to BMW and get the OEM part, it's $750 by the time you're
done and they still fail.

Another favorite is how they manage to use a vast assortment
of cable connectors that even upon careful examination, you
can't figure out how they come apart. And that's assuming you
can see it well, right in front of you.

I've had basic American cars that went 100K+ miles with
no CV boot joint failures. A friend just got rid of a
Honda CRV with 200K+ miles and no CV boot failures.
Friend has an X5 and it went through 2 of them in less than 75K
miles. At 140K, they're shot again. The rubber boot on
the intake manifold also failed at 75K. Obviously their rubber
boot products are crap, but they don't care.

Or how about their window system in the X5, where they use
crappy cables to hold the windows up? I've seen those fail
with the car sitting in the driveway. Cable snaps, window
falls down and smashes to bits. Not on just one window, I
saw it happen on two different ones in a friends car.

But, you're already planning on buying your next $75K BMW wonder
car, right?