fan control module test ?

Hi was wondering how can you test the fan control module and verify it is bad ? what kind of tests and specs am I suppose to perform. I know most of the time the a/c compressor doesn't kick on, the idle up does not function and the cooling fans don't come on like suppose to, but what kind of readings should I get out of the module ?? any help would be much appreciated.. thanks

That is real easy. If you swap in a good one, and it works it was bad.

If not troubleshoot the wiring attached to it for the expected signals.

I did swap in a new one and it did work. but I want specfic values. its a nice $185 guess each time if not