Root cause insight into the common BMW blower motor resistor

[Michael A. Terrell]

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.

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.

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.


--

Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

Sometimes Friday is just the fifth Monday of the week.

 

[Leif Neland]

Fřlgende er skrevet af Nate Nagel:

On 03/25/2013 01:58 PM, Bimmer Owner wrote:
On Mon, 25 Mar 2013 07:55:03 -0700, jim beam wrote:

that reduces the probability of it being rohs

What does ROHS mean?


Restriction of Hazardous Substances; that is, no lead (among other things.)

http://en.wikipedia.org/wiki/Restriction_of_Hazardous_Substances_Directive

This does not count the hazardous issue of the soldering failing,

causing hazards to the users of the equipment :-(

--
Husk křrelys bagpĺ, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.

 

[Scott Dorsey]

Leif Neland <leif@neland.dk> wrote:

Fřlgende er skrevet af Nate Nagel:
On 03/25/2013 01:58 PM, Bimmer Owner wrote:
On Mon, 25 Mar 2013 07:55:03 -0700, jim beam wrote:

that reduces the probability of it being rohs

What does ROHS mean?

Restriction of Hazardous Substances; that is, no lead (among other things.)

http://en.wikipedia.org/wiki/Restriction_of_Hazardous_Substances_Directive

This does not count the hazardous issue of the soldering failing,
causing hazards to the users of the equipment :-(

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

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

 

[jim beam]

On 03/28/2013 06:28 AM, Bimmer Owner wrote:

On Wed, 27 Mar 2013 08:35:09 -0700, jim beam wrote:

Bomarc has reverse engineered a lot of automotive modules:
http://www.bomarc.org/basement/viewtopic.php?f=1&t=6&sid=8ee707756ef37b24ff5aa633f1b4548a
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

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.


--
fact check required

 

[jim beam]

On 03/27/2013 09:33 PM, Michael A. Terrell wrote:

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.


--
fact check required

 

[jim beam]

On 03/28/2013 06:21 AM, Bimmer Owner wrote:

On Tue, 26 Mar 2013 15:51:52 -0400, tm wrote:

In your other pictures, the spring clips just hold the transistors against
the heat sink.

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.


--
fact check required

 

[jim beam]

On 03/28/2013 06:13 AM, Bimmer Owner wrote:

On Tue, 26 Mar 2013 19:52:26 -0500, Jamie wrote:

Most likely thermo stress cracks due to the potting restraint.

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.


--
fact check required

 

[jim beam]

On 03/28/2013 05:20 AM, Scott Dorsey wrote:

Leif Neland <leif@neland.dk> wrote:
F�lgende er skrevet af Nate Nagel:
On 03/25/2013 01:58 PM, Bimmer Owner wrote:
On Mon, 25 Mar 2013 07:55:03 -0700, jim beam wrote:

that reduces the probability of it being rohs

What does ROHS mean?

Restriction of Hazardous Substances; that is, no lead (among other things.)

http://en.wikipedia.org/wiki/Restriction_of_Hazardous_Substances_Directive

This does not count the hazardous issue of the soldering failing,
causing hazards to the users of the equipment :-(

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>


--
fact check required

 

[Bimmer Owner]

On Tue, 26 Mar 2013 19:16:06 -0500, Jamie wrote:

I can only assume the linear module at least uses a feed back to
maintain output voltage, if it is so cheap that it does not even
do that, then maybe they are trying to emulate a real resistor or
they are just shitty engineers or tightwads.

Most of the people on the BMW forums think it's one of these.

 

[Bimmer Owner]

On Tue, 26 Mar 2013 19:52:26 -0500, Jamie wrote:

Most likely thermo stress cracks due to the potting restraint.

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?

 

[Bimmer Owner]

On Tue, 26 Mar 2013 18:55:16 -0500, Jamie wrote:

Fluke T5-600, SKU: 133038, $109.95
It only does AC amps..

Good catch!

 

[Bimmer Owner]

On Wed, 27 Mar 2013 09:16:55 -0400, Scott Dorsey wrote:

Can you chip off enough of the araldite from the cover to be able to
read the numbers on it?

I will try this morning. (I was away on a trip for the past two days).

PS: Had to look up araldite:
http://en.wikipedia.org/wiki/Araldite

 

[Bimmer Owner]

On Tue, 26 Mar 2013 15:51:52 -0400, tm wrote:

Does the red jumper connect to the 40 amp fuse?

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

 

[Bimmer Owner]

On Tue, 26 Mar 2013 15:51:52 -0400, tm wrote:

In your other pictures, the spring clips just hold the transistors against
the heat sink.

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).

 

[jim beam]

On 03/28/2013 06:31 AM, Bimmer Owner wrote:

On Wed, 27 Mar 2013 18:37:20 -0700, jim beam wrote:

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,

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.

then what was the original purpose
of the potting in the first place?

--
fact check required

 

[Bimmer Owner]

On Wed, 27 Mar 2013 08:35:09 -0700, jim beam wrote:

Bomarc has reverse engineered a lot of automotive modules:
http://www.bomarc.org/basement/viewtopic.php?f=1&t=6&sid=8ee707756ef37b24ff5aa633f1b4548a
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]

On Wed, 27 Mar 2013 18:37:20 -0700, jim beam wrote:

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?

 

[tm]

"Bimmer Owner" <dontaskfor@mymail.com> wrote in message
news:kj1g34$7ot$5@news.albasani.net...

On Tue, 26 Mar 2013 15:51:52 -0400, tm wrote:

Does the red jumper connect to the 40 amp fuse?

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]

On 03/26/2013 09:03 PM, jim beam wrote:

On 03/26/2013 11:46 AM, Nate Nagel wrote:
On 03/26/2013 12:35 PM, tm wrote:

"Bimmer Owner" <dontaskfor@mymail.com> wrote in message
news:kisfan$ott$4@news.albasani.net...
On Tue, 26 Mar 2013 08:56:22 -0400, Scott Dorsey wrote:

one person figuring the failure mode out might save a
lot of people that grief.

But mostly it's just intellectual curiosity.

Exactly!


I don't even own a BMW. After this thread, I don't think I ever will.

Like I said before, don't drive one then. It's kind of like going on a
date with that unbelievably attractive female type who is also smart,
witty, fun to be around, actually seems to like you, and oh by the way
is completely mentally unhinged.

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


--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

 

[Cydrome Leader]

In sci.electronics.repair Scott Dorsey <kludge@panix.com> wrote:

In article <kigfbd$nq7$2@dont-email.me>, jim beam <me@privacy.net> wrote:
On 03/21/2013 07:23 PM, Nate Nagel wrote:

*why* is it overheating?

because it's linear, retard. if you don't know what they means, fuck
off until you find out.

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?