How do you know if the motor is good or bad?

There are several points to identify the motor: 1. First of all, from the perspective of factory labels, there are generally factory labels and packaging, and professionals can know the truth at a glance. 2. Product workmanship, European parts are relatively fine, followed by fineness, Japanese and Korean parts, American parts, China parts, and some American parts are made in China. 3. Try using a multimeter, and set it at Mega O, but not at 12V. 4 load test, the simplest method!