'99 Park Avenue with 44K runs and operates as well as can be but recently the A/C while fan is running stops blowing any air out the vents. The A/C is still working because I have felt the cold along the plumbing under the dash. The fan can be increased/decreased but no air can escape out any vent reguardless of setting.

This happened three times in a four hour drive yesterday. I turn off the system for a few minutes and then turn it back on and it worked fine for another hour or so then it malfunctioned again.

Any ideas would be appreciated.