HVAC making a clicking sound...

[Lostagain]

I have noticed since it has gotten cold that when I push some of the selector buttons on my heater controls that I get a wierd noise that doesn't stop unless I turn the engine off and restart the car. It happens on the heat setting and sometimes on the heat/deff setting. It is like a 'klop, klop, klop kind of sound...lol. Sounds like a little motor running in there. Are the doors on the heat system vacum actuated?

[Wiscon_Mark]

Is it a "something's stuck in the fan" kind of sound? That's the most likely explanation. When you hear it, crank it all the way up and see if it goes away.

[Lostagain]

Nope. It's not in the fan. It's kind of a slow noise. It klops like every second. It doesn't change with the fan speed. I've noticed that when it is doing it that it wont go all the way to heat. A lot of air comes up from the defrost vents. It probably has something stuck in the doors. I'll just have to tear into it when I get time.