Ac thermostat I turn the ac on and set the temperature. The fan comes on but the air doesn't. There is an * on the control. What do I do to remedy this problem?

So the ac is not working. Is the compressor running when you have the control set for ac ?

faulty thermostat switch

Please reply with Model number of bottom of AC unit ( upper) . Can be seen from inside usually. Thermostat model, plus if controls are at the ceiling assy or at thermostat on wall.

The breather hose should run to the air cleaner housing or intake tube.
Check your radiator cooling fan. If it isn't working the car will run hot at slow speeds or idle then cool down after you get going faster. A quick check would be to turn the AC on and see if the fan comes on. If not try lightly tapping on the cooling fan motor with a wooden broom handle. If it comes on then you have a bad motor.
If the fan comes on with the AC then check to see if the fan comes on after the engine gets hot. If the engine temp doesn't kick it on then the temperature sensor might be bad.
If the fan is ok please post more info on your problem

First off is it manual or automatic climate control ? Single zone or duel zone ? It's probably the front blower motor speed control ! electronics .

Let see if I can help. The numbers don't come up so we'll just try your information.

Exhaust - should be closed when using for Air Conditioning
Energy savings turns the fan off with the compressor when set for Air Conditioning
Fan Only means just that (no Air Conditioning)
Fan speeds Quite same as low, Norm same as medium, Super same as High
Temp settings, what the thermostat senses before cycling compressor.

About the only thing that you didn't list is the cooling fan. Are you sure that it's working properly? Drive the car until the engine starts to get hot. After awhile you should hear the cooling fan come on. After you have driven the car for a while, park it and open up the hood. If the upper radiator hose is almost too hot to touch, then check to see if the coolant fan is running. If it isn't, then turn the AC switch to "AC MAX". If the fan still doesn't come on, then a malfunction is indicated. Try to locate the fan control relay and swap it with another relay that has the same part number. Use a relay that will allow the engine to run. Allow the engine to reach operating temperature and see if the fan comes on after switching the AC switch to "AC MAX". If the fan now operates, then replace the relay. I hope this is helpful to you. Thank you for trying Fixya.com. If this does not solve your problem, then post a comment and I will respond by getting into more advanced diagnostics.

How did you determine that the sensor failed. Did the check engine light come on? When you say that the fan won't turn, do you mean that it won't turn on and run or that you can't physically turn it by hand. To determine this, disconnect the electrical connector to the fan and try to turn it by hand. It should turn easily. If it doesn't then it must be replaced. If it does then reconnect the electrical connector to the fan and try to operate it by disconnecting the temperature sensor lead and placing a jumper wire between the terminals of the harness. turn the AC control to AC/MAX and turn the ignition key to on. If the fan runs then the problem is the sensor. If it doesn't then check the fan control relay and any related fuses. WARNING : Use extreme caution when testing the fan circuit. Never attempt to turn the fan with the electrical connector in place. The fan can operate at any time even if the engine is off.

I think this fan is thermostatically controlled and only comes on when it is needed. It is supposed to come on immediately when the air conditioner is turned on. some cars have a temperature switch on the engine to control this fan.

If you have a standard thermostat the fan switch is for the air handler only. It completely over rides the thermostat for most settings. Now lets see this is what I'd expect:
fan switch on Indoor fan runs all time
Fan switch auto Indoor fan only runs when thermostat is set to cool or heat and the thermostat is turned up above room temp for heat or below room temp for cooling. In both of these modes the furnace blower comes on and stays on til the room temperature is satisfied. The outdoor unit only comes on for AC the out door unit will not come on for heat or the "on" setting on the thermostat. See exception 1 & 2 below...

Exception 1- (in a heat pump the out door unit runs in both heat and cool mode unless it has emergency heat turned on then it will not come on outside in the heat mode, and depending on the type of heat pump and furnace or air handler it is). A heat pump thermostat usually has "backup heat" and an "emergency heat" setting switch on the thermostat.
Exception 2 - On some thermostats they are made to cycle on the heat if the temperature reaches a preset temp (around 50'f usually but definitely by 40'f). This mode prevents freezing when if instance the homeowner is away or while the home is under construction. In this mode the fan inside can run but the heat usually comes on with it.
Exception3 - On some electric furnaces the heating strips may be individually controlled and thus not all come on at one time. This may give the feel of no heat especially if the room is cold.

Now there may be other exceptions but Ive tried to give you a heads up on some of the most common ones.
If you need more help please post more specifics about your unit/system as to for sure what switches are set to what setting and what is happening with each. My first though was that maybe your system is OK and you needed to know if the thermostat was working properly.

If this helpd you understand your problem would you please give me as hifgh a mark as you can. Thnaks for using fixya and good luck.