Is my dishwasher model 66515119K217 supposed to lock when doing the dishes?

Will not run without door locked. See if something blocking door, typically a dish, utensil or rack not all the way back.

Will not run without door locked. See if something blocking door, typically a dish, utensil or rack not all the way back.


But it does run and I can open the door.

But it does run and I can open the door.
If that is the case, the door safety switch has been compromised or the handle is closing the switch but not locking. Biggest danger is water damage to the floor.

This is a common problem caused by the adjustment screws loosening and throwing the microswitch and the lock out of adjustment. Remove the cover and adjust the switch and lock to be closed and locked when the door is locked. Here are manuals to help you: https://dl.dropboxusercontent.com/u/8010163/Kitchenaide%20Dishwashers.zip
https://dl.dropboxusercontent.com/u/8010163/Whirlpool%208178741%202008%20Undercounter%20Dishwa sher%20Service%20Manual.pdf
https://dl.dropboxusercontent.com/u/8010163/Whirlpool_Dishwasher_Service_manual.pdf
These manuals will show detailed instructions on how to fix it.