1000 ohm sensor on Invensys definitely not RTD

[David Friedman]

I spent some time today looking into whether my Acadia with the new
Invensys control board had good temp sensors. The Invensys board has
a diagnostic that can read sensor temps directly while preforming a
full test sequence of all of the compessor states. And guess what.
One of the three sensors was bad. (temps were all relatively close to
outdoor of 78 but two read 10K and one read 5K. Using the test mode -
two read through the PC board and showed reasonable temp accuracy and
one didn't read at all.

So I now need to find a source for the Thermistors. How do I know it
is a thermistor? Looking at the temp vs R curve given in the manual,
it is very non linear requiring a lookup table on the PC board to
interpret temperature. The very non linear R vs T with a large r swing
with temp is characteristic of a Thermistor.

I will start a new post on savemyacadia.org on this subject and
hopefully find a quality source.

David

[David Friedman]

Oops. Device is a 10K thermistor.