A/C Servo Motor Question w/Pics

[51.50]

Let me start by saying I'm not a mechanic, so I do not know the names of certain parts.  This is of a 2004 Porsche Cayenne Turbo w/ 4-Zone Climate

 

However, what I do know is, the A/C electric motor (955.624.915.01) under passenger side dash is steadily going back and forth regardless of A/C or Heat On/Off, High Low, Dash,Floor, Etc.  It connects to a flap on the passenger side firewall.  Pictures are of the same part, just different angles.

 

My question is this.  How do I test this electric motor to determine if it is bad?  Or could something else be bad causing the motor to constantly move?  Any response will be appreciated.

[bmats]

I had similar problem...every now and then the blower would work...I didn't know if it was the A/C and heater blower motor or if it was the blower motor regulator. 

 

To test your blower motor...you'll have to remove it to visually inspect it and turn it to see if it moves smoothly, if it doesn't move smoothly...then the bearings are likely shot...if there is black residue, then the motor is probably gone or is going. 

 

The regulator makes is so you can have different temperatures in each zone...my problem was i didn't get any air regardless of heat or A/C...therefore, I chose to replace the motor first and then the regulator if necessary. Lucky for me when I replaced the motor is fixed all of the issues. 

 

Here is a link to the plower motor and regulator at Pelican Parts. http://www.pelicanparts.com/catalog/SuperCat/1078/POR_1078_VENTHT_pg1.htm#item2

 

I hope this helps. Good luck!

 

 

  

[51.50]

I believe my explanation caused a little misinterpretation.  The blower motor seems to work fine.  Here is a picture of what I would like to test.  This is the electric motor that constantly keeps moving back and forth.  Or maybe someone can simply say, "Yes, if it is moving back and forth it is indeed broke."  My reasoning for not automatically replacing it is that I am not sure if this is the actual problem, or if it works fine and just receiving an incorrect signal from something else that may be bad.

 

[clarksongli]

Mine does the same thing, makes this mildly annoying back and form motion which also has a slight squeak too it when the flap moves.

 

What stops mine from moving though is when I put it in the "recirculation" only mode.  The valve shuts and stays shut.

 

I'm pretty sure it's not supposed to constantly move, I just have no idea why mine does.  Since mine closes and stays closed when I command it to, I figured it has to be something else telling it to open and close all the time.