I'm doing some basic checking of a 1995 6.6 L. I tested resistance of both CTS (coolant crossover pipe) and IAT sensors with digital meter, engine cold, about 65F. They read millions of ohms. Engine warmed up and read CTS of about 250 ohms; very close to chart values. IAT was still reading meg ohms. Bought a CTS and ohmed it out of the box; no reading at all. Store did not have IAT in stock so I didn't get it. All info on forums state these are temperature dependent. Are they really temp dependent, are they on/off at a set temp, did I get a bad CTS or something else? Thanks