I had a Check Engine light this AM on the 850, and the AC fan would not come on. I ran the diagnostics which returned a litany of error code. After clearing the codes, I ran the car for a little while with the AC on (and the fan running) and got the code "324: Floor/defrost damper motor active too long".

Is this an indication of a damper motor failure? One of the original codes was a "314: Floor/defrost damper motor shorted to earth or 12 volts", although that one did not reoccur.

Thanks,

Well, your CEL didn't come from the damper motor, LOL. If you are in the habit of having the switches in auto/auto mode, I suggest turning on/off the recirc a few times. Dust/dirt collects and slows things down. Just switch it off for 10 sec, then on for 10 secs, a few times.

Your CEL is probably from and O2 sensor and it will come back shortly. Look for a vacuum leak before replacing expensive parts.

Klaus

IIRC this means that the Damper motor was supposed to change something (either open or close one side or the other) and had 12 seconds to do it. It didn't get the job done which sets the code. When this happens the car goes into a defrost only setting where air only comes off the windshield.. The motor isn't currently running which could mean dead motor, or it could just not be functioning because of the 3-1-4. 3-1-4 means one of the wires leading to the motor is shorted and it cuts off the power to the motor until the problem is fixed. I don't know how often the motor checks if its fixed, but you can get it to run diagnostics. I believe you put it in auto/auto with a/c and recirculation, and a/c on as cold as it gets and start the car. It takes a couple of minutes then the car tells you what all is wrong...

Then check the codes, see if anything else occurred.
Then I'd check fuses 5 and 31 making sure nothing is amiss.

Then I'd pull out the damper motor and make sure its clean. I suspect its dirty and got clogged up. You have to pull out the glove box and its on the console side.

If you get 3-1-4 again then you have a different beast.