ac quits working after about 1 hour
 

I have an 05 GT. About a year ago the problem began. When I am driving for an hour or so, the ac will slowly begin to blow slower and less cold until it is hardly blowing at all, and the air is not even remotely cold. I have only noticed this occuring after an hour or so of highway driving. If I pull over and turn off the car for 5 to 10 minutes I get a few minutes of ac before it stops working again. due to the time driving required to make it fail, I have never been near my dealer when the problem occurs. I have taken it in, but the dealer claimed he was unable to replicate the failure. I really want to get this fixed before my warranty runs out. Does this problem sound familiar to anyone?

I guess you could drive it around until it fails and then don't shut it off when you get to the dealer until someone gets in the car with you to observe it. Pain in the butt, but no AC is worse IMHO.

Oh yeah, and welcome to TMS! You'll find lots of info and a great group of people here!

The A/C system is freezing up, I bet. This is common if the refrigerant (freon) gets low. Have the dealer check the refrigerant charge. I bet it is low.

A simple, but temporary, cure for future reference is turning off the a/c but leaving the fan blowing. Just push the a/c button off and leave the temp set to cold. Let the system blow until it blows freely again, then push the a/c button again.

The air is probably blowing warm since the air is not blowing quickly enough through the duct-work to keep it cold. The ice in the system constricts the airflow, and by the time it gets to the vents it has picked up lots of engine heat.

Thanks for the advice. It has gotten cold now (high of 40), but I will throw on a jacket and try to get it to fail today. I have today off, and the next day I have free will likely be colder. Wish me luck. It reminds me of the stupid cold weather game I played when I was 16, and I am getting way too old to play freeze-out.

I had this happen to one of my cars in the past. The a/c system is supposed to cycle the compressor off and on to prevent it from freezing up. I'm not sure what does this....maybe some sort of electronic thermostat module? :dunno: The dealership should have known to check this part out! Good luck-- I hope they can get it fixed for you soon.

I drove around until it froze up today, but when I got to the dealership they told me they did not have an ac tech there today. I called this morning to make sure they were open, but I did not ask if they had an ac guy scheduled. That will teach me to make assumptions. So its a frustrating morning and half a tank of gas later, but I have an appointment for Monday and for some reason I am still optimistic. I just love my car too much to harbor doubt in my heart.

The dealer shouldn't have to replicate the problem. They should have installed the A/C test gauges to verify the proper operation of the a/c systems refrigerant pressures.

Protection from dealer / technician abuse
 

:banghead: Like everyone here, I dread having to take my '06 GT into the dealer for warantee / TSB work due to the "technician abuse". I found that I can protect my car from a beating by placing a 2x2 inch stryofoam foam block under the carpet behind the gas pedal. This block is hidden from view, allows the car to be safely driven, and the car cannot be floored! Works like a champ. Swimming pool noddles have the correct density as well.
I have been trying to figure out how HERTZ was able to block turning the traction control off in their GT-Hs. This would also be a good counter measure. I have even heard of some who have taken one rear wheel off and put the spare on to discourage a burn out contest at lunchtime!
Feel free to offer up any other ideas to protect our cars! Oh yeah, I put GLAD bags over the leather seats to cut down on the post work clean up and set the tone at the dealership if that is possible.

Protection from dealer / technician abuse
 

:banghead: Like everyone here, I dread having to take my '06 GT into the dealer for warantee / TSB work due to the "technician abuse". I found that I can protect my car from a beating by placing a 2x2 inch stryofoam foam block under the carpet behind the gas pedal. This block is hidden from view, allows the car to be safely driven, and the car cannot be floored! Works like a champ. Swimming pool noddles have the correct density as well.
I have been trying to figure out how HERTZ was able to block turning the traction control off in their GT-Hs. This would also be a good counter measure. I have even heard of some who have taken one rear wheel off and put the spare on to discourage a burn out contest at lunchtime!
Feel free to offer up any other ideas to protect our cars! Oh yeah, I put GLAD bags over the leather seats to cut down on the post work clean up and set the tone at the dealership if that is possible.

I think the more junk like that you do to your car, the more likely the technicians will just laugh and abuse the car more. It's not like the tech's have never seen a mustang before, and are just waiting to go crazy on the first one they ever drive. The 05+ cars have been out for over 3 years now, and the dealers have seen plenty of them.