A/C sounds like it is blowing hard but it's not.

its failing

could be a leaking servo pipe. if it is knob turn type. motor failing on electric type. or a warn linc on vent control. very hard to find out you need to get your hand round the back and feel for the motor/s. on electric type. knob type with engine off move the vent control should hear a hissssing sound if no hissing sound then it is leaking.

Check the fuses, or the whole knob assembly went bad.

2004 mercury mountaineer.heat problem
When turning ac knob to heat clicking sound like door opening and closing repeatedly sounds and air blows cold instead of hot.

replace the knob

Need more information. The most important thing would be to watch the heater water valve move when someone turns the control from hot to cold, back and forth?
Heater valve controls tend to be operated by vacuum, and switched by a heater computer. Lots of possibilities. But first tell us what you see move when operated? Valve is usually in engine compartment, in the heater hose. Follow the hot one.

THE MOTOR THE CONTROL THE DOOR FOR VENTS THE GEAR ARE PLASTIC. ON THIS TIME REMOVE THE MOTOR AND CHECK THE DOOR BY HEAND IF DOOR OK REPLACE THE MOTOR CONTROLER.

Spirit93,

Yes! There is a switch in the dash your knobs goes into. it is bad if you have to hold it out to make contact. remove the dash and you will see the switch.

Good luck,
Lugnut61

check for vacumm leaks or disconnected vacuumm hoses around the in take manifold!

As far as the A/C goes. Does the A/C compressor turn on?? if so, than you may have a MODE door problem in the air box. Do all heater knobs turn freely or is one of the binding up?? I have seen the MODE door gears falling off and sticking the MODE door on hot setting. Test knobs for movement. If A/C compressor is not coming on, than you may have a leak and all freon leaked out or it could be just a simple thing like fuse or relay. Test to see if A/C compressor comes on. As far as the alarm goes, you need to switch your security from silent to non silent mode. Here is how its done. Hold BOTH lock and unlock buttoms together for about 5 seconds. (the directionals or sidelamps will flash)That will switch the alarmmode to NON SILENT and back to SILENT if you need to.