Hi TSO:
Read this thread: http://us.lexusownersclub.com/forums/index...showtopic=57291.
He had the same problem and traced it down to the car-phone ECU in the trunk! Apparently, a leak in the trunk intermittently shorted out the ECU and made it think that the phone had been lifted. Apparently, the "mute" feature on the phone cuts in. This mutes the radio and slows down the blower. Go figure!
Anyhoo, read the thread.
BTW, how did you fix your problem? You say that it was fixed, but please give details.
Cheers,
Robin