The motor has 5 wires. They are 1st gear, 2nd gear, 3rd gear, and 2 capacitor lines. Which one is good for motor maintenance? Generally speaking, except for individual motors, the colors of the wires in three gears are red, blue, and green, and the wires connected to the capacitor are black and yellow. Disconnect all 5 wires of the motor. Firstly, set the multimeter to the Euro range, with the red lead connected to any capacitor wire and the black lead connected to the 1st range. First, record the resistance value, and then measure the 2nd and 3rd gears. Normally, the larger the measured gear, the greater the resistance value between the capacitor line and it. Which company is good for repairing air compressor accessories? That is to say, if the resistance values of the above three gears are all infinite, or if a certain gear is infinite, it means that the motor coil is burnt or the coil of a certain gear is broken. Finally, measure if there is a short circuit between the 5 wires and the motor casing, that is, the ground.