AC Recirc/Max issue

Got in my truck this morning (Las Vegas) to run to a couple of meetings and noticed that while my AC was set to "max" and the "recirculate" button was depressed and the recirc light was on, it isn't recirculating. AC cools but does not recirculate. Blower controls are working- fan speed increases/decreases appropriately. No electrical smells in the cabin.

Suggestions for troubleshooting this issue prior to talking it to a shop? I'm assuming that recirc isn't a separate circuit. The light on the button comes on, it just seems to have no affect on operation.

Suggestions are greatly appreciated!

 

Just curious, how can you tell it isn't recirculating?

 

It makes more noise (not in a bad way) and moves more air.