Wow !! Ya got me kinda confused on what was replaced and the problem.
So, I'll give it my best shot in the dark and that is, you don't have an overheating problem and your heat selector switch screwed up a few times. You have heat inside but nothing to blow it around like it's suppose to, right?? Blower motor was changed also??
Best I could suggest and cheap is that there is a wire plug connection on the heater blower motor up in behind the dash. Tough to get at maybe but you're looking for a heavy black wire and a heavy green wire(unless they changed the wire code). This is only if your blower motor is working correctly and the selective switch is toast!! Once finding the two wires leading to the motor unplug the wire connection and then splice onto those going to the blower motor with a toggle switch/or some other multi-switch. With one good direct positive + lead and a good ground - lead hooked up then you should be able to control the blower motor to turn on and off when you want.
I'm only saying this because it sounds like you are having troubles getting your heat selector switch to run the blower motor fan.
If not correct me!! Gooooood Luuuckkk!!!