I have a Trane unit with GE condenser fan motor number 5kcp39fg. New condennser fan motor is A.O. Smith number F48k92A01. My question is on the old fan motor there were only 3 wires two for cap and looks like 1 for motor line and the new motor has a brown and brown/white for cap a black for line and a yellow for line what do I do with the yellow wire?

Cap likely hooks to brn and brn/wt.
Motor may have a Very small diagram on it.

I have a Trane unit with GE condenser fan motor number 5kcp39fg. new condennser fan motor is A.O. Smith number F48k92A01. My question is on the old fan motor there were only 3 wires two for cap and looks like 1 for motor line and the new motor has a brown and brown/white for cap a black for line and a yellow for line what do i do with the yellow wire?

I tape off my Brown & white wire and the yellow goes to what I call the brain not the cap or the compressor. This worked last time but now my unit is not working so who knows.

I tape off my Brown & white wire and the yellow goes to what I call the brain (Contactor) not the cap or the compressor. This worked last time but now my unit is not working so who knows.

Connect both the brown & the brown with white stripe to capacitor.

Connect the brown with white stripe to capacitor & the solid brown to capacitor & the yellow or black wire to contactor, should work.