Toyota Repair: air conditioning

Question
Hi Ted,

I have a 1998 Toyota Camry XLE, 140,000 miles, 6 cylinder. When I turn on the air conditioning in the highest and next highest fan position it makes a loud hum.  In the three lower fan positions it doesn't.  The cooling aspect is working correctly.

Is this anything to be concerned about?

Answer
Hello, it sounds like the fan is out of balance, possibly something inside, even a leaf that got in through the vents can cause noise, remove the fan motor assembly, it's located below the glove compartment and there are three screws that need to be removed and an electrical connector.