Disconnect the shuttle motor cable . Measure the resistance across the (2) pins at the end of the cable  from the motor. The correct resistance is between 5 and 20 ohms. Measure the resistance between each motor cable  pins and the ground cable. The correct resistance is open or infinite. If the resistance is not correct, replace the motor.Remove the tool changer motor cover. Make sure the proximity sensor or mechanical switch cables and the motor power cable  have labels for their conenction locations. Disconnect the cables . Remove the carousel motor assembly . Remove the cam follower assembly .
Push the carousel motor housing in the direction of the spindle to get access to the slip clutch arm . Manually turn the slip clutch arm  through 180° of movement. It should rotate smoothly, but with heavy resistance. If the arm does not move smoothly, replace the motor.