Looking for clarification on A/C clutch, fan, etc.

[teamgs]

Greetings,
My wife's 03 3.0 X5 recently experienced A/C failure. The A/C clutch won't engage, nor will the auxilliary fan start, either by turning on the A/C button, or by running the car until it reaches operating temp. (OBDII says it is 214 F) The cabin blower works, but of course, it blows ambient air. I had replaced the FSR a few years back for another issue.

I have:

1. checked the two small fuses for the A/C and the 50 amp fuse: all good

2. checked the power at the aux fan plug: 12.5 V dc

3. Until the failure, the A/C was working fine, so I suspect that the freon charge is fine.

I have a couple of questions:

1. Would a fan failure cause the system to not allow the compressor clutch to engage? I.e., is there a fan speed sensor?

2. Is there any way to test the fan itself; I.e. bypassing the system and simply applying 12 V?

3. Any other items to test?

Thanks in advance.

Gary