It is very possible that something could be obstructing the main pump. But, first. Does your dishwasher fill with enough water? When full, the water level should fill to just below the heating element. You can check this by waiting for the fill cycle to stop and the normal wash cycle to begin. Open the door and check the water level. If your dishwasher isn't getting enough water, you could have a bad fill valve, or the inlet water line could be kinked. If this isn't the case, then suspect that you might have a clogged pump. Food particles such as popcorn kernels, orange or lemon seeds, small chicken bones and glass are notorious for getting into the pump screen area and obstructing the water flow (some of the other items I have found are labels off jars, bottle top seals, twist ties, rib bones, hair scrunchies, and yes - even band-aids!). Even though some dishwasher manufacturers advertise some amazing capabilities of their dishwashers, you still need to scrape your dishes of all food particles as much as possible. This does not mean you have to pre-wash prior to loading them. Anything that doesn't get dissolved by the wash cycle and detergent will end up sitting in the pump well. If the pump isn't able to pump enough water, your dishwasher will fill normally, but the spray arms will not turn, detergent does not dissolve and your dishes will not come clean. To get to the pump, you need to remove the lower spray arm and the coarse screen (located directly under the lower spray arm). The pump well should be located under the coarse screen. Look for anything that may restricting the water flow. I hope this helps and it's easy fix for you.
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