Disposal runs but dishwasher does not drain, and water backs up into the dishwasher.

Safety first: Turn OFF power to the disposal and dishwasher. Avoid running the dishwasher until the issue is resolved.

• Check knockout plug: Disconnect the dishwasher hose from the American Standard disposal. Shine a light into the inlet. If you see a solid disk, the knockout plug was never removed. With power OFF, knock it out from the outside using a screwdriver and hammer, then remove the loose disk from the grinding chamber with tongs.
• Clear inlet: If the plug is removed, clean any buildup inside the inlet with a small brush.
• Inspect hose: Check the dishwasher drain hose for kinks, sags, or clogs. Flush it with water or replace if blocked.
• Verify air gap/high loop: Ensure the hose runs up to an air gap or high loop under the counter before connecting to the disposal, and that the air gap (if present) is not clogged.
• Test dishwasher drain: Reconnect the hose, then run a dishwasher drain cycle and observe for proper flow into the disposal.