If you want a software system to do a bunch of stuff, well that's what you're working towards here.

But if you think your fan is bad, and just want to do a more careful test before buying a new one, you don't need anything beyond a voltmeter (true RMS probably required).

There are multiple ways to trigger the fan to come on, and if the rest of your car (ECU, AC, ...) is working fine, they should all work. The simplest (to me) seems to be the one shown in post #24 by @Overboost. Turn AC on, pull that connector off, and the fan should be commanded to run at full speed.

Then you measure voltage on the control wire going to the fan, and see if it behaves like I describe in post #28.

If you see power and ground on the two fat wires in that connector, and the control wire voltage is measured as it should be ... and the fan does not spin ... it's a pretty easy diagnosis. Maybe not 100% certain, but watching the control voltage change as it should will confirm the control signal is not majorly wrong. Definitely easy enough to do before just buying a new fan if other testing methods did not work.

Also, even if you do command the fan to spin using a Foxwell, INPA, PASoft, etc., unless you actually measure the voltage at the connector going to the fan, using a scope or voltmeter, you won't be sure the problem is not between the Foxwell/ECU and the connector.

My Foxwell sends the control signal as well, with specifics listed by me earlier in this thread. My BMW Scanner PASoft clone thing probably used to, but decided to stop working when I tried it on this problem.

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2001 X5 3.0i, 203k miles, AT, owned since 2014