My aux fan quit 2 weeks ago also. I found this out when I left my car running in the drive with a/c on. I came out and the car was making a horendous ticking noise and then the a/c system discharged all my r13. My buddy who does HVAC for a living checked out the system. He said that without the fan working, the condensor could not properly cool the refrigerant so the high side pressure soared and the system dumped the charge. Luckily it took a new charge without a problem. I've ordered a new fan motor, but until I install it I'll only run the a/c while the car is moving.