[s-cars] Climate Control - Damn the Snowflake

[Vincent Frégeac]

Hi Manny,

IIRC, there is some malfunctions that would switch off the compressor (aka
snowflake off) while not triggering a fault code in the channel 1. These
malfunctions can be identified in the channels 52 and 53 with the help of
the guide on the 12v.org site.

You should give a look to these channels too.

Regarding the 8.7 code, a blocked temp flap will simply blow the same mix of
cold and hot air whatever the difference between actual cabin temperature
and desired temperature cabin. This will usually translate in freezing
driver in winter and boiling driver in summer, but this doesn't affect the
compressor and snowflake display. But since you had since code, it would be
a good idea to open the temp flap servo and recondition the brushes and
contactor in the little engine there's here. I've posted something on this
subject on the list years ago but I'm overloaded in June as usual, so no
time to go through the 5 years of S-Cars archives. To make a long story
short, remove and open the temp flap servo as per the write-up there is
somewhere on the audifans site, open the motor by pulling the two tab with a
small flat screwdriver, then clean the black deposit on the motor brushes
and contactor using the eraser of a pencil (you need the kind of cheap, sand
paper like, eraser found usually on pencils. A nice, smooth erase such as
the Steadlers won't work. Beside, the eraser on a pencil has a diameter
close to the contactor diameter which help cleaning the brushes without
changing their shape. Be cautious when you remove parts from the motor, most
of them are very small and love to jump into the most remote hidden places
of your work area.

If you need me to find my write-up on flap servo motor refurbishing, you
should contact me once in July when I'll have more time available. BTW, you
can also search for information about reconditioning motors in electric RC
cars. That's how I learned the best tricks about reconditioning electric
motors.


Vincent

-----Message d'origine-----
De : manuelsanchez at starpower.net [mailto:manuelsanchez at starpower.net] 
Envoyé : 22 juin 2007 09:13
À : djdawson2 at aol.com; munrof at sympatico.ca; rit_bellis at hotmail.com;
s-car-list at audifans.com; s.sikss at gmail.com
Objet : Re: [s-cars] Climate Control - Damn the Snowflake

Fellow S-heads,

I checked all the codes in the CC Head per the 12v.org site (Thanks Vincent)


Currently there were no stored codes in any of the channels that would list
faults, such as Channel 1, System Malfunction. Channel 1 read 00.0.

I found some old paper work in my records where I had done this a year or so
ago, and the code stored in Channel 1 back then was:

8.7-Temperature Regulator Flap-Sporadic Block

Would the 8.7 code cause the snowflake to come on and off (I somehow think
that would be an unrelated symptom, like when I occasionally would get hot
air coming thru the vents even with the climate control blower off)?

I checked the channel for the compressor speed (Channel 29) relative to
engine speed (Channel 28) and with the multiplier (Compressor=1.28 x engine
speed) all seems fine. I am correct in assuming that if there were ever a
discrepancy between the 2 speeds a code would show up somewhere in the
system diagnostics or are these 2 channels like the channel that display the
speed of the car, an actual value at that specific moment in time that is
not stored? In other words, when the snowflake goes off the next time, I'll
need to toggle to those channels to see if at that exact moment the speed
differential exceeds the stated 1.28 multiplier value?

Thanks again for any insights.

-Manny
95.5 UrS6 Avant (Flaky Snowflake)