Xonopa

Frequently, nearly always, when I turn on my car, [IS300 2004 model] even before starting it, a rather loud noise comes from somewhere under the dashboard on passenger side.

It sounds like a small motor trying to set the AIRCON ducts?

It continues about 30 seconds then stops.

At times, it continues and if I change the aircon options as to where the airflow should concentrate, it stops.

Rather INFREQUENTLY, this happens randomly even when the car is NOT turned on. This I seldom catch, but I have noticed it a few times now.

Thanks!

harlockssx

One of your three HVAC actuators is going bad. Have someone turn the car on while your head is underneath the dash to try to isolate which one it is. Replacements are around $135, depending on which one it is.

Xonopa

Thanks for your response. It seems quite correct.

BULLITT1

to help diagnose system, I recommend adjusting one a/c setting(****/switch) at a time, through the full mode/range of switch/**** until you can verify which servo motor is malfunctioning.