Air Conditioner is stuck on

1999 MERCURY SABLE STATION WAGON
10,000 MILES • 3.0L • V6 • 2WD • AUTOMATIC
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TONYWOOD
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  • 3 POSTS
Air conditioning system will be turned on whenever an climate operation switch is not positioned Off (blow fan is always on once the operation switch is turned from Off position at any mode even air conditioner is not selected ). Because of air conditioner is always on, the car gets only cool air and no heat regardless where temp dial is at. The car engine cooling system has just replaced new very recently, including a new heater core.
Apr 20, 2016 at 11:28 AM
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HMAC300
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  • 48,601 POSTS
try pulling hvac fuse inside car it may be the blend door is sticking or needs to reset, pulling fuse may reset it. if heater is in defrost position ac will work as well.
Apr 20, 2016 at 12:11 PM
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TONYWOOD
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  • 3 POSTS
Tried to pull the AC fuse (#6) from battery junction box. The AC system seems stopped working completely when turned on the engine. It went to back with the problem once the fuse was put back in. The blender door seems working normal. Also tried to pull the AC clutch fuse (#33) )from the power distribution box. This will stop the AC clutch from engaging, but not stop the AC fan running.
Apr 21, 2016 at 7:41 AM
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HMAC300
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then get it scanned for codes it may be a hvac control problem
Apr 21, 2016 at 8:20 AM
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TONYWOOD
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Did. Get no error code.
Apr 21, 2016 at 8:50 AM
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HMAC300
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  • 48,601 POSTS
a mechanic has to scan it not an auto parts their scanner will not pick up codes of this type
Apr 21, 2016 at 9:25 AM