Buzzing sound coming from behind and bellow blower controls.

[vtchequers]

When I turn the key to the on position, there's a buzzing sound coming from the foot wells on both sides, bellow the blower controls..
The hot/cold air dial position effects the loudness of the buzz, It's louder If I turn the dial to full hot position.
The buzzing stops if I turn the dial to a certain position.
It happens with the blower off.


Car is a 2000 Vauxhall Zafira, so doesn't have automatic climate control.

Edited by vtchequers on Monday 7th September 23:37

[vtchequers]

I've narrowed it down to the Heater Flap Motor/blend door actuator.