996 2002 996 AC fan low volume problem

[herm5000]

List Mates, I have a 2002 996 c4. When my Air conditioner compressor is activated the volume of air coming out of the vents is decreased dramatically.  It still blows cold but just very very low volume or amount. I have had it recharged , checked leaks , replaced condensors etc but nothing changes. As soon as you switch the ac off ( snowflake button) the volume of air through the vents goes right back up.  Volume of air is fine on heat , defrost etc.  I have never had this issue with any other vehicle. Any ideas as to what the problem may be?

[DBJoe996]

Stupid question - are you running it in the Auto mode or manual mode?  In other words, what happens if you switch the AC on and use the FAN button to increase the airflow?

[Ahsai]

The air volume is low even if you set the fan speed to full speed? Sounds like an air distribution issue to me. Any error code of the unit (e.g., read by Duramatric or Porsche scanner)?

Edited October 2, 2018 by Ahsai

[herm5000]

no error codes and it doesn't matter if auto mode or manual. as long as ac is on the air is choked down. you can push the snowflake button and it will choke it down. Push it again and air flow boosts right back up. Still coming thru same vents so don't think its distribution but who knows.

[DBJoe996]

Hate to say it but it seems something is wrong with the HVAC control panel.  If I push the snowflake button, that engages the AC compressor to pump freon through the system, and I can manually put the fan speed anywhere from low to high, and direct the air manually to defrost vents, dashboard vents and floor vents, any or all of these.  To put the system in maximum cooling mode, hit the snowflake, put the temp control on LO, push the recirc button, push the dashboard vents button, and manually put the fan on HI.  As far as I know, when in this mode (or for that matter any other mode other than AUTO), the fan speed is independent of the AC mode and operates anywhere from LO to HI.

 

So it comes back down to...why when you engage the AC does the fan blower not manually operate from LO to HI?  It should.  So I think something is wrong with your HVAC control panel.  Another question, what does your voltage read when you engage the AC?  Does it drop a lot or stay fairly steady at around 13V?