The wires look fine. You can do a continuity and resistance check on the heater and motor to make sure they're not open.

Relays are mechanical things, it could physically fail and short out the control side and send a whole bunch of power to components not sized to handle that kind of load.

There's also large temperature changes and humidity. Both are tough on the control board.

I would try to figure out what happened and then prevent it from happening again.