My unit is leaking and the outside drain pie is bone dry. I cannot find the tube or pipe from the unit out to look for a kink or crack or to see if it is clogged. Can I use a compressor to blow out any possible clog ?

"my unit is leaking" on the floor or what? You're a coil should drip condensate into a pan under the coil but you must have the inspection door open to see the pan, have you done that yet?

Yes I have opened the unit up. The water is on the floor and the unit stands on a built up base . The pan is full of water .

OK then your drain is plugged. Siphon off the water or use a turkey baster to get the level down. Drain is normally in the front corner and you'd see a pipe coming out through the side wall of the furnace. This pipe directly or indirectly drains to a floor drain, sink or condensate pump.