There is a strange sound (scratching or rubbing) coming from behind the glove box in my 1999 RX300 The noise is intermittent and occurs even when the key is turned to the accessory position. It continues to occur with engine running. The blower motor is not the problem. My Lexus repair manual mentions 3 servo motors in the a/c/heater system. I suspect the strange sound is coming from one of those motors. Can anyone suggest a way to determine where the noise is coming from?