If you look at the start light it will be flashing.
You need to count the number of flashes from it in between the pause and let me know.
Ok 3 flashes is a heating error code.
To clear the code you need to press and hold the start button for several seconds and that will reset the control board.
Then see how it goes from there. But if it does it again then theres a fault on the heater circuit which can be either the heater itself, wiring or the control board.
But usually on these dishwashers its the heater that causes this fault.
But reset it and just see how it goes from there.
If you need anymore info just get back to me.
Ok so when you press the start button what actually happens?
Is the start light lit?
Ok strange that it wont start now after resetting it.
Try this and see what happens.
Turn the dishwasher on and select the rinse cycle.
Turn the dishwasher off
Press and hold the start button and keep held in.
Turn the dishwasher back on and wait till the start light flashes then let go of the start button.
Now press the start button once and close the door.
Now it will run a 12 minute test cycle so just leave it and see how it goes.
Once it starts to wash you can just open the door and press the start button once and close the door and it will end the cycle early.
Once it stops then retry it and see what happens from there.
Nice one fingers crossed that's sorted it but if it does go again and flashes 3 times then its something to do with the heater circuit.
Is it the instruction manual you want or a service manual?
As to be honest Whirpool don't do service manuals for the appliances im afraid they only do like test sheets and error code lists.
The test sheet is the test you have already done and if you want a list of error codes just get back to me and I can see if I can upload them.
There isn't anything like a manual that shows how to take them apart or test the parts im afraid.