I have a Maytag dishwasher, same age, I believe the same model. My bet is that it's the control panel, especially if the heating element seems fine. Ours has been doing similar things --started with a blinking control panel, which was fixed by a 1-minute unplug reset. Now even resetting it does nothing to fix the erratic control panel. Buttons are acting erratic, and the machine started itself the other night. I've read --and just looking at it, I can see that-- this series of dishwasher has a design flaw: the steam vent goes right by the control panel wiring, which causes corrosion, which shorts out the panel over time. I came here myself to see if there was a tutorial for reinstalling a new control panel/touchpad, which is what I think we're up against in our case.