Put a volt meter across the motor
(meter set to DCV to test a 12vdc motor). If you see normal voltage when your radio control makes the unit go click, then the problem is in the motor
or the gearbox
If you have voltage at the motor & nothing spins, check that the connection at the motor is clean & tight. If it looks good, then attach a clamp-on amp meter. If it draws no current
, then you have an open circuit & the motor probably needs brushes
, a rebuild
or replacement. If heavy current flows, but nothing spins, then you probably have a short or a mechanical jam. If you don't have an amp meter, then you can often confirm heavy current flow by the motor getting hot.
If the foot switch works, but the radio doesn't, then there is probably a problem in the radio gizmo or it's connection to the same relay that the foot switch operates, assuming that the foot switch uses a relay. If the foot switch is a direct mechanical connection to a massive switch, then the foot switch may not use a relay.
I don't know your winch in particular. These are general comments.