A couple of things need clarifying. What is it about the heater that doesn't work? No heat at all? No fan? Fan only on high? Coming out the wrong vent?
For no fan at all, the quickest test is to unplug the fan and check if it runs when wired directly to 12 volts. If it doesn't, your fan motor is dead. If it does, look for a wiring fault, or perhaps a bad fan switch. For fan only on high, the problem is the resistor pack (located on heater beneath the glove box - follow the wires to a small dome-like cover. It's under that). Coming out the wrong vent = a vacuum problem. Look first at the line that runs beneath the battery and runs to the vacuum reservoir behind the right front bumper. The line can be eaten up by battery leakage, and the reservoir can crack. For no heat at all, first check your coolant level, then check the vacuum operated valve in the engine compartment.
When you say "tranny fluid," and refer to the master cylinder, I hope you are just being sloppy in your description and are actually saying you replaced the clutch master cylinder and filled it with BRAKE fluid. If not, more information is needed here too.