Kitchen aid KDTE104DSS0

[Oldjunk52]

My dishwasher will jot cycle It fill up with a bit of water then it stops When I push “ Cancel” it drains I ran a Diagnostic cycle on it for the full 23 mins but there were no error code So I put it in “normal wash” & it did the same thing thing  I notice is that the blue light on the upper right corner of the door never came on
Could it be the relay switch on the float

[Dash]

It is probably NOT your float switch.  First thing I would check is if the main wash motor is getting 120V.  After your dishwasher fills with water there is a pause but then main wash motor should turn on.  You'll have to remove dishwasher from your cabinet to have access to the main wash motor plug because it's at the back.  Use a Volt-Ohm meter to see if main wash motor is getting 120 Volts after dishwasher fills.  If it does, main wash motor is bad.  If it doesn't get 120 Volts, then electronic control board is bad.

FYI, I change lots and lots of main wash motors and electronic control boards on Whirlpool built dishwashers (KitchenAid, Maytag, Jenn-Air, Amana, etc.).