Hello, I have a 2003 S Type V6 that has the occasional hot air from the passenger side vents when in Auto mode, doesn't seem to happen when manually setting it on Lo or Hi. The issue I have though is after 10 minutes or so the air stops blowing out of the vents all together. This happens most frequently if the blower speed is at a low setting. I can change which vents the air is directed to but no air other than "seeping" air comes out of anything (dash vents, floor, or defrost). The blower continues to run and when I turn the blower speed to high the fan is loud and has a "cavitating" sound as if there is a complete blockage not allowing any airflow. To reset it and get airflow again I turn off the HVAC for about 10 minutes and turn it back on everything is fine for another 10 minutes. I suspect a blend door may not be holding open but not sure which one would block all airflow, the ones I've read about seem to be about blending air and such. Thanks for any suggestions.

 

If you let it stop then turn up the heat a few degrees what happens?

 

I usually just run the HVAC in either Hi or Lo temp setting and not in Auto mode so the fan speed is just manually controlled. But to your question if I did have it in Auto and turn up the temp (or down for cooling) the blower speed will increase to try to satify the setpoint but with no airflow it just blows on high and doesn't do any good. If I turn it off for a few minutes then hit the Auto button it "resets" and comes back on and works fine for a while.

 

I don't know anyone who has run it as you do and can't think of what it ought to do...

 

The icarsoft 930i or similar scanner will give you any climate control
Codes if there is an electrical system failure causing it ! Like servo or module,
But may be Try a hard reboot ( battery disconnect wait a min
Then touch the two battery leads together for a min then reconnect batt)
You will have to reset hand break afterwards ! Also make sure you have
The stereo code if applicable!

 

Thank you, I will try a hard reboot and find somebody with a scanner to see if there are any codes.
Like this morning coming to work it was 40 Deg F and I had the HVAC set in Auto mode to 74F, it got to the setpoint in about 10 minutes then a few minutes after that I could hear the blower motor speed increase because the temp was falling and it needed to catch back up, but by then a door or something closed and there was no airflow out of the vents so the blower fan just blew on high speed and never warmed the car up.

 

The hard reboot did not do any good. So I'll find somebody with a scanner and see if there are any codes to go off of.