The blower motor fan is ever so slightly hitting against a balky flapper door of some sort and making a soft clicking sound. I can get the door to close (or open?) completely by switching the front windscreen defrost on/off - then the clicking goes away. I presume it is an aging plastic connection or weak actuator of some sort.

Can someone point me in the best direction?

Thanks!

 

It is a good possibility that pieces of the interior insulation in the system are causing the noise. Take a look in JTIS and you can remove the bottom of the air units and try cleaning out the interior. Since the noise will go away by changing the blend door position I would try cleaning first.
While you have the bottom off you can examine the pivots on the blend door and make sure one of them is not broken causing you noise.

 

[Take a look in JTIS and you can remove the bottom of the air units and try cleaning out the interior. [/QUOTE]

I can't seem to find a description of this process in the JTIS, can you tell me where it is?

Thanks!

 

I will take a look today and get back to you.