My wife's ML has just satrted to make a strange noise in the adsh which seems to be related to the HVAC system.

When the temperature control is on its coldest position, there is a tick tick noise from near the center vent about once per second. If you advance the temparature control 2 "notches" above the coldest setting, the noise goes away.

The position of the directional setting seems to make no difference. Do I have a jammed vent door or something??

Gilly??