Re: Funky Voltage Reading from Climate Control

[steveb@falcon.kla-tencor.com (Steven Buchholz)]

 # In cold weather (generally below 20 degrees F) when I go to "Channel 11" on
 # the climate control for a voltage readout, the readout indicates a solid,
 # unchanging 12.0v.  The gauge on the dash tells me that I am really at about
 # 13.5v and I do not appear to be draining the battery.  A recent trip of
 # over 200 miles running the lights, seat heater, and defrost did not
 # deteriorate the cranking power of the battery (restarted cold at 4 degrees
 # below zero....Vermont...go figure).  At some point, the reading comes back
 # on the climate control....when the outside air is warmer or the car is
 # sitting in traffic for awhile...and reads a normally fluctuating 13.4v to
 # 14.0v depending upon any number of variables.  Anyone else experience
 # this...impending doom of some kind?  ....or just more Audi fun?
 # 
... I'll bet you're using your climate control blower when the voltage 
measurement is lower.  In typical Audi fashion :) the CC head is in the 
same circuit as the blower, and the gauge of the wire is such that you 
will get a significant voltage drop when the blower is running.  This 
is a common situation for Audi ... in my old '78 Fox the voltmeter would 
drop to ~8V when the blower was running at full ... and this voltage 
drop usually caused the temp & pressure gauges to read higher ...

HTH!

Steve Buchholz
San Jose, CA (USA)