I have an 11 SHO with 73k mi. At idle in the summer the a/c even when set to max will blow warm air. Again this only occurs at idle even though the car is at normal operating temp. When the revs are up whether in drive or in park, the air temp is as it should be. The dealer has been useless in diagnosing. "Cannot recreate condition" The water pump was changed at 51k mi. I have bled any air from coolant system as described in shop manual. I had suspected the water pump was failing again and the dealer wants no part of it since the water pump is under 2yr warranty and they would have to eat the cost to replace for the 2nd time. The dealer claimed no codes were detected. The dealer found no issue with the cooling fans. The max engine coolant temp when running was ~220°.
After I had posted the above a couple months ago, I had replaced the cooling fan control module shortly thereafter. I had realized this when I was wiggling the module's plug with the car at operating temperature and with A/C on; as the fans would turn on when I wiggled the plug. When I stopped, the fans would turn off and A/C would blow out warm. The module is located on the cooling fan. I secured a GATES module from RockAuto, as a Ford/Motorcraft part is NOT available from Ford or anywhere. I cleaned all electrical contacts on the harness plugs (there's 3) and installed the new module. The A/C now functions properly and effectively at idle, as well as at speed. Icy cold again! Also the engine temp peaks at ~210 and quickly drops to 190 and lower as the cooling fan kicks in.
Thus check your cooling fan module.
After I had posted the above a couple months ago, I had replaced the cooling fan control module shortly thereafter. I had realized this when I was wiggling the module's plug with the car at operating temperature and with A/C on; as the fans would turn on when I wiggled the plug. When I stopped, the fans would turn off and A/C would blow out warm. The module is located on the cooling fan. I secured a GATES module from RockAuto, as a Ford/Motorcraft part is NOT available from Ford or anywhere. I cleaned all electrical contacts on the harness plugs (there's 3) and installed the new module. The A/C now functions properly and effectively at idle, as well as at speed. Icy cold again! Also the engine temp peaks at ~210 and quickly drops to 190 and lower as the cooling fan kicks in.
Thus check your cooling fan module.
