Most of the used winches we’ve bought didn’t work under their own power when we looked at them, and every time it came down to the solenoids. With disuse, especially if a winch sits outside for a while, it is fairly common for the solenoids to get stuck. On winches that can power in and out, all the solenoids are doing is switching polarity to the poles on the motor. If the solenoids are stuck, you can go straight from your battery to the motor to check the motor. Sometimes you can smack the solenoids and unstick them, but sometimes you need to buy new ones. In a few rare cases, the controller or wiring has been messed up. But whatever the case, if the motor works and you don’t hear any grinding, it is usually a good bet that you just found your new-to-you winch.