grinding noise under dash on 01 Ram

[smantas]

I have an 01 Ram with a 5.2.

Problem is I hear a grinding noise under the dash when I switch from heat to cold. I have no problem with getting heat or cold but it sounds like an electrical motor that moves the blend doors, and doesn't want to stop after the door has moved.

there is a flat small electric motor under the dash on the passenger side right next to the hump on the floor that constantly runs even when the heat controls are shut off.

When accelerating it quiets down but at an idle it sounds as if the doors keep opening and closing and it's noisy (squeeks and grinds)

Any help would be appreciated......Thanks!