I just replaced the external fan for my ac unit. The original fan had 3 wires and the new one has four. The instruction indicate that all wires may no be used and to just insulate the one I don't need. Here is my problem, I keep blowing my external 30amp fuses and tripping the circuit breaker. I know this means I have created a short but for the life of me I can't figure out how I have it wired incorrectly. Before I started blowing fuses I did get it to work but the fan was turning counter clock wise instead of the way the original fan turned which was clock wise. I reversed the white and black lines( per the instructions) with the idea that the fan would turn clock wise, this is when my trouble started so I tried to go back to the way I had it wired but with no luck and I am now completely confused and lost. The capacitor has only added the confusion since I did have it wired to work and it did get the fan started but as I mentioned I tried reversing the white and black. I have basically tried so many configurations I am completely lost on what did work and the wire diagram that came with the motor is lacking to say the least... help

p.s. it's a lennox

What is the model number of the "outside unit"? What color wires were on the old motor, and what color wires are on the new motor? Most likely the extra wire is brown with a white stripe, if so that can be capped off, white and black go to the T1 and T2 on the contactor and the brown wire will go to the terminal marked "fan" on the capacitor. When you purchased the motor you should also have purchased a matching capacitor, if not, I advise that you do so.

What you forgot to tell jas is that you can't change the direction of that fan by playing with the wires. You have to BUY THE RIGHT MOTOR. Shaft rotation is determined by facing the shaft of the motor and then applying the terms clockwise and counter-clockwise. Remember analog clocks?

It has to fit mechanically.
It has to be the proper voltage.
Speed/speeds must be close.
HP should be close.
You should purchase a new capacitor.
Doesn't matter if 3 or 4 wire motor if single speed.
DIRECTION should be correct.

True, I guess I missed that part of his post. Either way, we need a little more info.

You didn't give us all the wire colors with the fan motor you have. You did get a new run capacitor with the new motor didn't you? Motors are rated for different capacitors and a wrong one will cause high amps and trip the breaker or over heat the motor. If you just have Black,White,brown and brown with a white tracer. The two browns go to the run capacitor black on one side of the contactor white on the other side. To reverse the rotation will not involve any of those four wires but just the four that connect to each other at the bottom end of the motor by switching the colors around. For instance red to red, orange to orange clockwise. Red to orange, red to orange counter clockwise.