Winch problem

[Jon Stratis]

When you tell a motor to stop, all it does is supply 0V across the leads. This means that the motor can backdrive, which is what you're seeing. You have two options... Tell the motor to go "up" very slowly in order to hold its position, or implement some sort of mechanical brake. Keep in mind, stalling a motor (telling it to move while not letting it move) will cause heat build up. Depending on the situation, it's possible to burn out a motor by stalling it too long.