Dishwashers Wont Drain When In Its Cycle

I Have Two Matag Dishwashers That Will Not Drain When In There Cycle, I Have Cleaned Many Times,checked For Blockage In The Drain.(none). I Thought It Might Be The Timer, So I Replaced The Timer At A Cost Of $150.00. I Also Replaced The Float At The Same Time. No Luck. I Found This Site After I Ordered A Drain Pump Assembly And Would Like To Know If That May Be The Problem. I Was Not Aware Of The Fact That There Is Two Impellers.

if the motor runs it almost has to pump.The drain impellar is protected pretty well so unless the wash impellar is trashed the machine wouldn’t wash either.They are pretty easy to tear down it all comes apart from the inside if you remove the drain hose at the pump with water in tub does water come out the port? …sorry does it have a separate drain pump?