AM-14 'Hot Motor' l.e.d staying lit.

1. The motor has thermistors( http://en.wikipedia.org/wiki/Thermistor ) installed internally. They are monitored by the control board to protect the motor from overheating and burning itself out should a fork or some other object find it's way into the pump and jam it.

2. More than likely, the thermistors have gone bad. I've yet to see the hot motor led light for any other reason.

The board can be "tricked" into thinking the motor is cool at all times but it requires bypassing the overheat protection circuit. Replacing the motor like you stated, is the proper thing to do. I'd be really surprised if after replacement your light didn't go out. All the best.