I got a color wheel from an old projector, and I would like to see it turning. It has 4 wires, but I have no idea which to connect. Any suggestion how to know to which wires I apply power?
This is most likely a Brushless DC motor, which require special circuitry to handle commutation, you cannot simply 'apply power' and expect it to run..
In its former life, your 3-PHASE BRUSHLESS DC. MOTOR was typically connected to this family of driver chip.
See a typical application on page 10 and the pins 5-8-9-and 10 connections to the motor..