OAT read fail?

[colin cohen <102621.2256@compuserve.com>]

I have been trying to solve a OAT reading problem on a 92 100/A6 Q for some
months now.  The read out suddenly went to -40C and no amount of poking around
and cleaning the sensor has helped. With some advice from the list and the
dealer, I bought a new sensor. Replaced the old one yesterday, no change!. I
have the Bentley which says nothing about the wiring except its multiplug
position and that it exists.

Methinks the next step is to get the dash out and check the wiring, except that
is not going to tell me anything except continuity and resistance which I
presume is ok because I get a reading, albeit the wrong one........ideas?