It's now fully into summertime here in ABQ, NM and I've been having a problem with my A/C.

The fan blows really cold for about 10 minutes, but then the cold cuts out and I'm getting unchilled (i.e. HOT) air coming out. This happened on the drive home. The cycle of cold/hot kept up for a while before the system finally stopped providing any cold air whatsoever.

So now I'm trying to figure out where my troubleshooting should start. Should I check the pressure on the system to see if I have a freon leak? I'm not sure this is the problem since the system does provide cold air for a while (outside air temp >83 deg).

Is this a clutch problem (I looked for a free-spinning clutch but couldn't see anything)?

Is this a calibration problem (if so, how do I recalibrate)?

I'm trying to avoid a trip to the mechanic, but I'm having a hard time explaining to my carpool mate that the cabin air temp will eventually be cool if he can just wait another 10 mins.

Any advice/help/etc. is greatly appreciated!

Thanks.

 

Well, tried to recalibrate. Got a "0" on the display, but then the display went to "Off" and the fan kept going. I tried rebooting, but the fan still won't go off.

Now I'm faced with a draining battery.

Any ideas?

 

My car is doing the same thing, fan will not turn off even when key is out and car is off. Let me know if you find a solution and i will do the same.

 

It's the ACC Fan Control Unit. Located under the glovebox to the left side of the psgr footwell. Rumored to be a high fail item. Cost to replace through the dealer is $130. Couldn't find a much better deal out there so I went with the guys who can guarantee it.

Here's the guide to replace it yourself: Link.

The guy who wrote it did an outstanding job with the guide. Wish they were all this good.

The job takes approx an hour, so plan on at least two!

Good luck. Will follow up if this really fixes it or not and how it failed.

 

Well, the fan control unit fixed the fan problem (i.e. wasn't shutting off). The dealership installed it for me (no labor cost) so they could troubleshoot the intermittent A/C. Seems there's a sensor running of the DICE module that they believe is failing. That part'll cost $81 plus tax and two hours of labor.

Arrgh...

But I'm inclined to let them fix it for saving me an hour on the ACC fan control unit replacement