My Prizm is making a noise that seems to be related to the blower but sounds like it is coming from behind the control panel/radio. Even changes volume and stops with bumps. I am going to check the blower motor motor, but sound doesn’t appear to be coming from the dash area where I believe the blower motor is. Anybody have any thoughts what else it may be?
You are probably correct…change the blower motor speed and see if the sound changes…if it does then pull the blower and clean out the box it lives in. Leaves and debris often find their way down there…
Blower bushings are probably worn and the fan is wobbling around.
I’ve removed a blower motor and tested it on the kitchen table using two 6VDC lantern batteries connected in series. It doesn’t take much power to run these motors. If the motor is shot, you’ll hear it in testing.
Another possibility is outside debris has found its way down from the ventilation slots under the windshield to the fan cage and creating a mechanical interference.