I have a Rheem furnace that is at least 10 years old, could be as old as 20. I had to replace the blower motor which was a 1/4 hp and the motor I replaced it with was able to be 1/8, 1/4 or 1/2 hp. Depending on how it is wired. From reading on the capacitor I could hook this up as a 1/2 hp which I figured would give me a stronger air flow. The wiring was not exactly the same so this is what I did, I wired black to black for what I assume is the high side for the a/c and I wired red to blue which I assume is medium for the heat. I had a white wire and a brown wire from my old motor that went to the capacitor, one on each side. The new motor has two brown wires for the capacitor and plugged them in but to the same side of the capacitor and not the way the old was, one was on one side and one on the other. The blower motor will come on but only stay on for about a minute then goes off, not heating the house. Where did I go wrong ?