If you do take the fan motor resistor pack out shine a flashlight into the hole and check the evaporator. You may find that it's pretty dirty. The dirt's usually stuck on pretty good so a vacuum doesn't work very well. I've spray the heck out of it w/ brake/carb cleaner which seems to work but you have to be CAREFUL 'cause the stuffs usually very FLAMMABLE. Be sure you blow it all out with lots of compressed air. You don't want your dash to explode when you turn the fan on.

With the ac on you can short out the pressure switch plug pins with a wire and the compressor clutch should activate. If it still doesn't activate try connective 12 volts from the battery directly to the clutch wire. The ac doesn't have to be on for this. If the clutch still doesn't click it may be bad or the comprssor ground wire could be broken or loose. It's usually connected to one of the rear compressor mounting bolts. Good luck..... "Old Guys Rule" !!