Regarding the ur-Q injector cooling fan temp sensor. My previous 86 5000CST injector
fan would rarely come on but my latest 89 200TQ injector fan comes on most of the
time after shut down. My 89 200TQ uses a 035 959 481C sensor (90 degrees C) .
I tested the sensor and it does indeed close at around 90 degrees C. It reopens at around
75 degrees C. It also has 140 degrees Max printed on the sensor. The temp sensor may
be designed to reopen if the temp gets over 140 degrees C to prevent the fan
from running during a fire under the hood. The 200TQ sensor looks like it mounts the same
as the ur-Q sensors.
Over the weekend at the PNW Audi get together one of the ur-Q owners mentioned that he
replaced his injector cooling fan temp sensor with a lower temp sensor as the stock
sensor rarely turned on the injector fan.