lincoln towncar 2003 blowing hot air from my airconditioner

There are several components that can cause the A/C not to work. With the hood open and the engine running, does the A/C clutch engage when the A/C is turned on? You should hear the clutch engage with a click and the engine would slow down a bit. If the clutch doesn't engage, it could be a fuse, a relay, or the system is low on coolant. Unfortunately, you will have to hook up some gages to the A/C system to see if it is low.

Air conditioning work is not for inexperienced home mechanics like me, so i usually go and pay a fee to have a reputable Dealer (really!) go over my car, tell me what's wrong, and take it to a smaller garage (cheaper!) if i cant afford the dealers repair estimate.