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Arthur, you must be getting pretty close to induction into the automotive Hall of Fame by now>
Couple of more weeks...............
The Default fan is open circuit detection by N22 module and it is an engine over-heat protection circuit so you don't blow the engine if that sensor circuit has a failure....it has nothing to do with the ohms value of that sensor..it is triggered when it it sees open circuit/failure anywhere in the temp INPUT circuit for the N22 module and that includes wiring harness, connectors, and sensor..
So , if sensor fails, wiring fails , open circuits , etc...the high fan Defaults to protect the engine in the event that system is not working at the same time an over-heat condition exist..we just use that info to trick the N22 module into thinking there is an OPEN circuit by unplugging the sensor so we can Verify the high fan circuit w/o getting out meters and schematics, etc. It is just another Trick Of the Trade to accomplish a quick, positive diagnosis..
Same deal with the low fan ..we know that you can simply fool the cut-in relay for low fan for a/c by jumping the high side pressure sw. to verify the low fan circuit. And these test take nano-secounds to do and cuz we are a lazy sorts..we do not do all the complicated checking you see posters mention..we just go to the heart of the diagnosis with our bag of tricks.