Our central ac unit is blowing air, but the motor is not kicking on. The start relay clicks when you turn on the termostat, but the fan doesn't turn, nor does the motor hums. How can you tell if a central ac start relay is going bad? Also we have purchased a new fan motor, and decided to change the capacitor and run capacitor, our old fan motor had 5 wires (brown, black, purple, orange, and yellow); the new fan has 4 wires (brown, white, black, brown-white, ground). We know where all of the wires connect other than the white wire, which is the common wire? Where do you connect the common wire? Here is a wire diagram for the new fan motor:

Brown/White- 370 VAC
White- Common

Can you tell me where to connect these wires to make sure we have them connected properly. Can't afford a tech, so I have to make it work!

The different colors of the wires of the new fan motor is confusing us!