BobL43
DIY Senior Member
To me, that rotary switche is used in an auto reset function if the unit trips on overload, to allow th emotor to cool for x amount of minutes, currently set (hard to see in photo) at 2,=45 minutes.Auto reset is not necesarily a good thing, especially if there is a constant problem, which there seems to be. The corrosion may be as you said from mineral deposits from the water, or as Don says, from leaked caps.