Installed a used Bosch dishwasher. Ran a test regular wash cycle. It went through the full cycle and even signalled the cycle was complete. When the door was opened water was still circulating in the bottom (pump was running). Drain line from dishwasher is clear from unit to high point vent/drain.
When I tried to cycle on/off the unit returned to draining mode, but still no dishcharge to the drain.
Where should I look first, second, third, etc…
The drain pump sounds like it’s stopped so you’ll want to check for a blockage. There is a video that will show you how to do this in the link below.
Double check the connection at the disposal if its hooked to one, if not remove any reducer you have on the line going into the standpipe.
If you are certain the drain motor is running and not draining sounds like you have a bad drain motor. You can access this and replace it from the front. Remove the lower kick plate and depress the tab on the drain pump it will twist out to be replaced or reveal some debris.