OK, I had the classic resistor pack failure mode - fan would intermittently cut off, and only run on speed 4. After about a minute or two, the fan would run on the lower speeds for a while, but them it would cut off again. This repeats over and over. This doesn't happen every day, but it seems to happen most on the hot days (although I seem to remember it happening in the winter a little bit?)

I had the same problem 9 years ago, and diagnosed it as the resistor pack. Replaced it ($11), and everything was fine. So I ordered a new resistor from the same favorite california supply place ($44!), and put it in. What?? The Blower fan is still doing the same thing! Didn't fix it.

Did I get a bad new resistor pack? Or could it be a different problem? Is there a way to test the resistor pack - especially since it is intermittent?