My 17-year old Kitchen Aid Dishwasher won't start sometimes. I am suspecting the door interlock switch. I can usually get the thing to work if I open and close the door 5-10 times. I can hear the typical sound of a micro-switch engaging, but I guess there might be an internal continuity problem with the switch. Maybe worn or corroded contacts? Is this a common problem with these units? Is it hard to replace the switch?

thanks for your help
DS@home