AC in the summer. It blows air but when driving highway speeds, I finally get c

Hey! Based on what you have written seems that the vehicle is most likely low on refrigerant. We would be more then happy to check out the issue you are having.

Possibly - A/C condenser/radiator *cooling fan* issue .. When vehicle is sitting or in slow traffic, fan should turn on with A/C on .. Don't need the fan while running at highway speeds, > got ram air then A/C operation is normal .. Recommend professional 'hands-on' diagnosis.