Root cause insight into the common BMW blower motor resistorfailures

[Bimmer Owner]

that at least is vaguely useful

I wasn't sure how to cross reference using that list.
For example, it had only one BMW entry (camera module); and it did not have
GKR or Sitronic or Valeo brands; nor the keywords FSU, nor FSR; but it did
have things titled "blower motor controller), e.g.,

FORD F50F-19E624 heater blower motor controller ('97 L. CONNIE) 1

 

[Bimmer Owner]

i don't know who you think you're talking to, but i have consistently
advocated /not/ deconstructing this unit. it's not worth it when cost
of replacement isn't that high or you can build an alternate controller
that will be more reliable.

Regarding cost, it seems we can get aftermarket parts for about $100;
and the part at the BMW dealership cost about $175.

Regarding repair, some have intimated that unpotting and resoldering
is a solution.

If that's true, then that might be a viable "fix".

However, I must ask: If it works without potting, and especially if the
potting is what's causing the problem, then what was the original purpose
of the potting in the first place?

 

[jim beam]

I wasn't sure how to cross reference using that list.
For example, it had only one BMW entry (camera module); and it did not have
GKR or Sitronic or Valeo brands; nor the keywords FSU, nor FSR; but it did
have things titled "blower motor controller), e.g.,

FORD F50F-19E624 heater blower motor controller ('97 L. CONNIE) 1

maybe it's similar, maybe it's not. the fact that each of the different
unit manufacturers has different internals and that they've changed over
time doesn't help you.

 

[jim beam]

Apparently I'm talking to a blowhard troll.




Ass. The first step in designing a replacement is to understand what
it is supposed to do, and how the original performed that function.

no???? really? are you /sure/ about that??? or doesn't sarcasm work
for you???

Show us.

no, you're doing that.

Send me some defective modules, or quit trolling.

they're not my modules [again, you're not following the thread] and i
wouldn't replace them - i'd pwm the motor instead.

 

[jim beam]

This implies two transistors (although I only found one).

I will dig through the mess again - but I think I was too fat thumbed
when I cut it open, and may have destroyed the evidence.

I do have a second FSU (since two failed on me) though ... but I want
to try to FIX that one (instead of destroying it).

dude, give up on that already. you'll never get good thermal contact
second time around.

 

[jim beam]

Other people have suggested this also.

Some say the potting is what is causing the stress cracks.

Re-insert without potting, is the "said to be" solution.

One question:
If the FSU works without potting, what was the purpose of the potting?

to keep the elements out. and the inquisitive.

 

[jim beam]

That's why there are exemptions for the military and telecom industry,
where it's actually important that stuff work properly.

What I find ironic is that the shorter lifespan of consumer gear caused by
the RoHS manufacturing has actually increased the amount of electronics
going into landfills, making worse the problem that it was intended to reduce.
--scott

and yet, some say that there can be increased reliability.

<http://en.wikipedia.org/wiki/ROHS#Reliability_concerns_unfounded>

btw, if you want /real/ reliability, you wire wrap.

<http://en.wikipedia.org/wiki/Wire_wrap>

 

[jim beam]

Regarding cost, it seems we can get aftermarket parts for about $100;
and the part at the BMW dealership cost about $175.

Regarding repair, some have intimated that unpotting and resoldering
is a solution.

If that's true, then that might be a viable "fix".

However, I must ask: If it works without potting, and especially if the
potting is what's causing the problem,

that's bogus. unless there's been a MAJOR screw-up, potting compounds
are carefully matched to the thermal and chemical application - they
serve to increase reliability, not degrade it.

 

[tm]

The red jumper was a hack added by one user to fix the solder cracks,
I think.

I am aware of that. It looks like it ties the two collectors together. But
does it go to the contact that connects to the fuse? The main point is "do
the collectors (center pin on transistor) connect to the 12 volt input to
the module"?

Thanks,
tm

 

[Nate Nagel]

no, what you're experiencing is her "disappointment" at discovering that
you are an anosognosic retard.

On this one subject I have no doubt you have personal experience, unlike
most of your posts.

nate

 

[Cydrome Leader]

Nothing wrong with linear motor control, it's just inefficient and
produces a lot of heat. I used to work in a place with a 1.2 MW DC
motor whose field coil voltage was controlled by a couple rooms full
of cast-iron resistors. The resistance array lasted nearly 80 years
before the whole facility was taken down.

I've got ask- what was this motor used for?

pumping station? mining equipment steel mill?

 

[Scott Dorsey]

I've got ask- what was this motor used for?

pumping station? mining equipment steel mill?

You could call it a sort of wind tunnel. Now obsolete, in great part due
to computer modelling making analysis tools like that less important, and
in great part due to computer modelling of the tools making it possible to
make less turbulent tunnels.
--scott

 

[Jamie]

I've got ask- what was this motor used for?

pumping station? mining equipment steel mill?

Just to blow a lot of HOT AIR around, and it seems to work!

Jamie

 

[jim beam]

Sure you do. That's why it's mostly been abandoned. It was bulky,
and had horrible crosstalk unless you resorted to twisted pair
signaling. It is crap at higher frequencies. If you want to go back to
<5 MHz hardware, it's perfect.

stop being so bent out of shape that you can't think straight old man -
i didn't say it was better at any of those things. i said it was more
reliable than solder. and it is.

 

[jim beam]

jim beam wrote:

i don't know who you think you're talking to, but i have consistently
advocated /not/ deconstructing this unit.


Apparently I'm talking to a blowhard troll.


it's not worth it when cost
of replacement isn't that high or you can build an alternate controller
that will be more reliable.


Ass. The first step in designing a replacement is to understand what
it is supposed to do, and how the original performed that function.

no???? really? are you /sure/ about that??? or doesn't sarcasm work
for you???

and credentials don't work on usenet - they're completely uncheckable
and many are bogus. what matters is whether you can walk the talk.


You can't even crawl.

at least i can follow a thread without being a crotchety old fart.


Show us.

no, you're doing that.

as for having stuff in orbit, i don't have anything, but two of my best
friends do. the difference between them and you is that they're not
jaded and they're actually helpful.


Then tell them to reverse engineer it for you. Or can't they 'walk
the talk', either?

i don't /want/ to reverse engineer it any more than i want to repair
broken light bulbs. you were the one bragging about how easy it was. i
said it wasn't. and when it comes down to walking the talk, you won't.


Send me some defective modules, or quit trolling.

they're not my modules [again, you're not following the thread] and i
wouldn't replace them - i'd pwm the motor instead.

Without knowing how to interface it to the vehicle.

??? if it were my vehicle, i'd be able to find it out now, wouldn't i!!!

What a lame ass
lying idiot.

whatever you say dude, but the fact is, i've done it before and i'd do
it again.

You demanded that I do the reverse engineering

i didn't demand any such thing, i pointed out that if you did, since you
were bragging about having done so much of it, you wouldn't be making
everyone have to listen to you piss and moan. but here you still are,
pissing and moaning since i guess it's so much easier, even for an
expert like yourself.

 

[jim beam]

How many deigns have you selected the proper potting compounds for?
What types of filler materials? How did you verify that no moisture
would be trapped inside the potting? Did you verify the temperature
coefficient of very component, the PC board material and the housing?
Test it for extended periods over the entire temperature, humidity and
barometric conditions that it can encounter in service. how about
vibration & impact testing? Or are you just blowing more smoke out your
ass.

wtf is eating your ass tonight? you're right that all those factors are
relevant. that's why i said potting compounds are "carefully matched".

as to moisture, you're attacking a straw man. i specifically didn't
list every possible application detail because it's common knowledge to
anyone doing that work. nobody specifies that any more than mechanical
drawings specify conventional right-hand threading on fasteners. /all/
fasteners are right hand threaded UNLESS left hand is specifically detailed.

 

[Cydrome Leader]

You could call it a sort of wind tunnel. Now obsolete, in great part due
to computer modelling making analysis tools like that less important, and
in great part due to computer modelling of the tools making it possible to
make less turbulent tunnels.
--scott

so there was an 80 year old giant windtunnel somewhere?

 

[AMuzi]

so there was an 80 year old giant windtunnel somewhere?

You're joking, right?

1901:
http://airandspace.si.edu/wrightbrothers/fly/1901/wind.cfm

very modern 1935:

 

[Nate Nagel]

so there was an 80 year old giant windtunnel somewhere?

well, 80 years ago would be 1933; definitely into the era of commercial
flight, so it's entirely possible. Hell, the Germans might have been
working on jet engines by that point, or at least thinking about them.

nate

 

[Jamie]

wtf is eating your ass tonight? you're right that all those factors are
relevant. that's why i said potting compounds are "carefully matched".

as to moisture, you're attacking a straw man. i specifically didn't
list every possible application detail because it's common knowledge to
anyone doing that work. nobody specifies that any more than mechanical
drawings specify conventional right-hand threading on fasteners. /all/
fasteners are right hand threaded UNLESS left hand is specifically
detailed.

Let me offer you some good advice, put him on your black list so it
won't eat you up. I only see him in replies now, like yours here because
I have block him out of my reader.

He's nothing but an old bickering dried up prone. In his younger
years he most likely good off on little kids learning the field and made
him
feel like he was something else when he offered any knowledge that he
thought was useful to them. These days, the little kids have grown
up and most likely found out that half the information he fed them was
bogus!

Don't worry about what he has to say, he's one of those that wants
every one like you, to kiss is feet and say how much of a god he is.

It should be obviously that will never happen from this end

Jamie