It may be that the short to earth is related to the heating element - something nearly shorting in the core of the element warms up and expands and touches the case perhaps.
You may have gone overboard taking out the motor and the pump - electrical shorts are not always easily visible.
BTW - 10 years is a long time for an appliance - we get only 8½ from ours so you're doing very well.
Good luck...
Peccavi, November 2009
