Heater control

We won't even go near the "check engine light" question. That's another story. We have a 2001 Ford Windstar 215,000 km or so.6 cyl I think!

We have a fan that works, and the rear defrost light knob works as well. But the slider to get the air from cold air to heat, doesn't work. We just get cold air. Also if we mess with it too much, it just starts knocking or clicking until we figure out how to shut it off again.

A parts store here in Kitchener, Ont. Suggested that it was the little white plastic piece (accentuator motor I believe) that is inside the heater box.

I thought it might be a loose connection or something come undone. We've been trying to remove that front panel in the dash where the heater and stereo us to see if we could see what might be the problem.

Is there any way we can fix this ourselves by buying the heater box or is there any point in even trying to take the panel out? Or should we defer this to the "expensive" professionals at the dealership.

Any light you can shed or hints as to what the problem might actually be would be greatly appreciated.

Thanks,
Joyce Allen
Kitchener, Ont