Outside Front Temperature Senson

[flderoos@mmm.com]

My outside temperature suddenly started reading approximately 12 degrees (F) 
low.  I checked the resistance of each of the outside sensors (NTC 
thermistors) and found that the one under the windshield measured 
approximately 1 k, while the one by the AC condensor measured 2.4k.  From what 
I could find, the control module displays the temperature from the sensor 
reading the lowest temperature (highest resistance) and ignores the other 
sensor.  Since my front sensor was so much higher in resistance than the other 
one, I was always sensing outside temperature witht he front one.  Anyway, I 
disconnected the front one and now read the correct temperature using the 
windshield sensor.  The only problem is that engine heat makes the reading 
high until sufficient air passes over it to cool it down to the air 
temperature.  

Now the question, does anyone know the specs for this thermistor?  I purchased 
six different thermistors from Digikey and plan to plot their resistance 
versus temperature.  I am also going to use a resistance box and plot the 
temperature indicated by the control module versus the resistance.  Then 
hopefully I can find a thermistor that matches the curve.  

Most thermistors cost in the range of $0.75 to $3.00.  If I can find a 
replacement, some other uses would be to measure additional temperatures, such 
as the inside temperature, differential temperatures and Torsen temperature.  
All it would require would be a small multiposition switch and mounting the 
additional thermistors.

I know the simple solution is to just buy the thermistor from Audi, but they 
want $92.65 for it which means that they are charging a factor of at least 15 
in markup.  Anyone know the 25 degree C resistance and the temperature 
coefficient of this thermistor?