How do you fix air conditioner in a 1996 Ford Taurus?

Not enought information here. "Fixing it is almost always easier than finding the problem." First you check all the vehicle fuses and especially the AC circuit fuses. 2nd you check the system freon pressures with a set of auto air service pressure guages. Can't do it? Then you need to learn how the AC works,where the parts are located, and get a diagram(road map)of the electrical circuit. Type in "Auto air conditioning" on your search engine and read articles on theory and operation of air conditioners for several hours. Find diagrams and pictures of the components of an auto air system. Go to your local Library and check out a Taurus service manual, or buy an Auto air conditioning book at your local auto parts store. You need a VOM meter also to check voltages and connections. Now,try to find your Taurus AC compressor. With the engine running and AC on low temp - is the front outside plate on the compressor turning? NO? That is the clutch and it is controlled by the AC on/off switch, climate control computer, or the low freon pressure switch and maybe several other switches. The compressor has to pump freon and if the front plate of the compressor is not turning then the clutch is not engaged. With the engine off the freon guage pressure should be 90-120 lbs. No Pressure? No gas - you have a freon leak. Running - the low side should be 50/60 and the hi side 140/160. These are examples only. When you get some knowledge on the operation you may be able to come back here and be a bit more specific about the problem and someone may be able to point you in the right direction. You fix it yourself - you will love it. There's a few out there that would like to have 5-11 hundred to fix it. That would buy a lot of ice and maybe a vehicle with working AC. LOL