I am replacing a 1990 Emerson Fan Motor (1/3 hp,1075 rpm, ccw) for a home air conditioning unit with a 2007 Dayton replacement motor (4M206G) and need help with the wiring.
Original Emerson has Yellow, brown, and black wires. New Dayton has brown, brown/white stripe, black, and purple wires, and a green ground wire.

Clip and cap off the brown with the white tracer wire its not used on the new motor. Put the purple in the yellows spot and the black in the blacks spot and the brown in the browns spot. You just made a four wire hook up to a three wire hook up. You did get a new run capacitor with your new motor didn't you? Your new motor may take a different size capacitor.

Most/all the new morors I`ve installed lately the instructions on the side of the motor tell you where the wires should go, and they instruct you to put both the brown and br/white strip wire on the new capiciter,, one to each side,, a new capiciter is a must and very important

The reason for the brown with the white tracer, is so you can identify and cap off the right wire for a three wire install.