Rhythmic clicking when HVAC options selected

[jbenal]

I have a 1996 240SX SE. When I select one of the HVAC options, I hear a rhythmic clicking noise from the passenger side of the center console. This clicking occurs when I select all combinations of vent options EXCEPT face and floor vent, when the clicking goes away when the face and floor vent button is engaged.

I removed the HVAC control panel to get a look on the inside and found the small motor on the passenger side of the console, between the heater unit and cooling unit, to continue to turn after a HVAC selection is made, causing the clicking noise.

Before I tear up the entire dashboard to replace the motor, I have a few questions:

1. Is it possible to diagnose this motor without disassembling the entire dashboard? My concern isn't the faulty motor, but a faulty selector switch. I'd hate to disassemble all of this if I don't have to.

2. If this small motor is the problem, what is the name of the motor? I've consulted the Nissan service manual and it's either called the Intake door motor or the Air Mix Door Motor, depending on which schematic I'm using. My online parts vendor (Rock Auto) doesn't list either one in their catalog. I'm sure there's a part number on the motor, but again, I want to disassemble the dashboard once. Plus, I really don't want to disassemble it to get to the motor, and then have to wait 3-5 days for parts with my dashboard in pieces.

NOTE: This is not the motor that operates the door which directs air to either the defrost vents or the other vents. That's on the driver's side and seems to work properly. I suspect that this motor opens the vent which allows external air to enter the system, depending on whether you select air recirculation or not. Oddly enough, that button has no impact on the clicking noise. Only the "face floor" button does.

3. If anyone has some tips on how to replace this without taking the dashboard apart, I'd love to hear it. I'm not looking forward to that job.

Thanks in advance!

[jbenal]

As a follow up, I found this part, the acutator assembly, at my local Nissan dealer. ($66 plus tax). Actual removal and installation wasn't very difficult with the help of a small, ratchet type screwdriver/nutdriver, available at any Lowes or Home Depot. I was fortunate in that my hands aren't overly large and able to work my way behind the center console. All works fine now.