Also I have a Rheem Model RBHA 17J11NFGAI Air handeler inside with a Rheem Model # RPLA 030JAZ heat pump outside. Last week I replaced the Thermostat (for economical reasons) and apparently purchased the wrong one the one I need is about $40 more so I put the old one back on. Made sure the wires landed as they did originally since I did write them down. NOTHING!! Read about a fuse but have searched everywhere for one and can't find one. After more reading it said it is near the circuit board but I really have no circuit board on the inside of the airhandeler only found one outside and didn't see a fuse. After even more research one site said the airhandeler could be in the attic is this true? I hooked the red,green,and yellow to test for power and got nothing. Please help me.

If you are sure you don`t have a circuit board with a automotive type plug in fuse (in the board) chances are that you might have blown the transformer. Its very easy to do if you didn`t kill the power(breaker off) to the furnace when you was hooking up the tstat wires