2006 Mustang GT Convertible; air conditioner doesn’t always work. When I press the button to turn on the air conditioner, the panel light illuminates but the a/c compressor does not engage. After driving the car for anywhere between 10 and 45 minutes, the compressor clutch will engage and the air conditioner cools normally. When I first noticed this problem over a year ago, I discovered that if I left the air conditioner in the “on” position when I turned off the car, the air conditioner would work the next time I started the car. This hasn’t happened lately (so much for that “solution”). The car has been at the local Ford dealer multiple times for this problem and although they have been able to duplicate the problem, they have no solution. The dealer checked the electronics, recharged the system and tested the computer and told me that these were all fine. Any help would be appreciated.
Sounds like a bad relay or sensor in the A/C system. My vehicles use what is called a “clutch cycling switch”, which is a pressure-operated switch in the refrigerant line near the condenser. Not sure if Fords do this the same way. An intermittent sensor like this will cause your problem. So can a bad climate control system in the dash.
If the mechanics can’t find the problem, they’re not trying hard enough.