2001 330xi: Climate control fans surges and wanes

My climate control fans surges and then drops off on my 2001 330xi. It
seems to happen when I'm either using auto control or when I'm using
the manual controls. The current temperature here in Philadelphia is
around 50-70 degrees Fahrenheit. I'm seeing the problem with the
heater/cooling fan surge at all temp settings....it seems to come and
go. Any thoughts. Could it be a filter? I'm perplexed because it comes
and goes, but seems to happen most of the time when I'm driving
(especailly when I slow down, for example). Thanks!

In article .com>,
> wrote:
> My climate control fans surges and then drops off on my 2001 330xi. It
> seems to happen when I'm either using auto control or when I'm using
> the manual controls. The current temperature here in Philadelphia is
> around 50-70 degrees Fahrenheit. I'm seeing the problem with the
> heater/cooling fan surge at all temp settings....it seems to come and
> go. Any thoughts. Could it be a filter? I'm perplexed because it comes
> and goes, but seems to happen most of the time when I'm driving
> (especailly when I slow down, for example). Thanks!

Almost certainly the final stage resistor.

--
*Caution: I drive like you do.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote:

> In article .com>,
> > wrote:
> > My climate control fans surges and then drops off on my 2001 330xi. It
> > seems to happen when I'm either using auto control or when I'm using
> > the manual controls. The current temperature here in Philadelphia is
> > around 50-70 degrees Fahrenheit. I'm seeing the problem with the
> > heater/cooling fan surge at all temp settings....it seems to come and
> > go. Any thoughts. Could it be a filter? I'm perplexed because it comes
> > and goes, but seems to happen most of the time when I'm driving
> > (especailly when I slow down, for example). Thanks!
>
> Almost certainly the final stage resistor.
>
> --
> *Caution: I drive like you do.
>
> Dave Plowman London SW
> To e-mail, change noise into sound.

I agree with Dave. Although now instead of a resistor pack it is a
transistorized control unit. Just had the one in my 97 328 fail recently.

Frank

In article >,
Raybender > wrote:
> > Almost certainly the final stage resistor.

> I agree with Dave. Although now instead of a resistor pack it is a
> transistorized control unit. Just had the one in my 97 328 fail
> recently.

Interesting. It's know as 'the hedgehog' by the trade in the uk due to the
rods sticking out the back which I assumed were resistors placed in the
air steam for cooling. I've not got a wiring diagram for my car.

They appear to have improved. They seemed to last just over a year when I
first got the car, but this present one (the only one I had to pay for)
has done three so far. They must have cost the maker a fortune in warranty
replacements.

I kept my old one intending to open it up to see what is inside but ran
out of tuits. ;-)

--
*Am I ambivalent? Well, yes and no.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote:

> In article >,
> Raybender > wrote:
> > > Almost certainly the final stage resistor.
>
> > I agree with Dave. Although now instead of a resistor pack it is a
> > transistorized control unit. Just had the one in my 97 328 fail
> > recently.
>
> Interesting. It's know as 'the hedgehog' by the trade in the uk due to the
> rods sticking out the back which I assumed were resistors placed in the
> air steam for cooling. I've not got a wiring diagram for my car.
>
> Dave Plowman London SW
> To e-mail, change noise into sound.

Hedgehog - that's right. I couldn't think of the word when I was writing my
reply. I used to think the presence of the microfilter tended to reduce the
airflow through the vents, compared to my other car, but when I pulled that
hedgehog sucker out it was apparent that those cooling fins are at least as
much to blame.

Frank

Thank you....sorry, didn't check back for a few days (was on a business
trip). Will get that checked out, then. Final stage resistor. Hmm.

Ah, I see this one now...transistorized control unit. Thank you very
much. Off to the shop then, I suppose.