I noticed my AC only blows cold air when the car is moving. So I took a look at the radiator fans and they weren't spinning. I checked the fuse near the battery and it appeared fine. Any suggestions on what to test next? The car is a 2006 M35x. Thanks.

See EC-516 here:
https://www.nicoclub.com/service-manual ... 5%2Fec.pdf
The fans are DC units controlled for variable speed by the Cooling Fan Control Module, which is basically just a giant Solid State Relay. It gets a PWM signal from the IPDM on the Violet wire telling it how fast to run, the signal should show up as a varying voltage on a voltmeter as the engine heats up. The module also needs good power on Red and good ground on Black/White. If it has all those then the module is dead.

Thanks VStar650CL! That is very helpful. I plan on testing the module in the next couple days. These last few days have been in the high 90's so I've been driving my backup vehicle because working outside on the car was going to be brutal! I'll post an update afterwards. Thanks!

It is most likely the Cooling Fan Control Module. I've replaced 2 of these over the life of my M. Fairly simple to replace. I posted a step-by-step a few years ago. Do not buy an after-market module. Get the Module from Infiniti online. I learned the hard way. I first bought an after-market Module and it failed within months. Good Luck!

Good news - the Cooling Fan Control Module tested out fine. Bad news - both fan motors were dead. Luckily, I found a pair of used ones on eBay so I didn't have to buy the whole fan shroud assembly for twice the cost. Swapped out the motors over the weekend and I'm back in business! Thanks all for the help!