The upper rack dishes are not getting cleaned with this machine. With the help of a few threads here and there on the internet, I've ruled out a lot of issues that it could be.

I've cleaned out every bit of debris, I've run the washer with it pulled away from under the counter, and even with the door open and lower spinner removed. I'm sure that the check ball is working correctly, and that water is being diverted from the lower spinner to the upper two. The problem remains that only the upper spinner spins, the middle one does not.

It seems to me that maybe too much water is coming out of the upper spinner, not leaving enough pressure for the middle one to spin. The upper spinner broke a while back, so the one on there is a replacement. If too much water was coming out of that, could it keep the middle one from moving?

I'm also thinking that maybe the middle arm is just broken. It does have a lot of play in it, but I'm not sure if maybe that is normal. The motor is really pushing water out of the lower spinner when that one is going, so I don't think that would be the issue. Still, something is keeping the middle one from spinning.

It's been suggested to me, and I tend to think this is right, that either the motor is not running as strongly as it should be and needs to be replaced, or that the middle spray arm itself has malfunctioned and needs to be replaced. Both of these solutions seem to make sense. Does anyone have any experience with this? Thanks.

Thanks for your reply, Gene. Yes, I've checked that connection, and the seal is tight. I ran the dishwasher while it was open, and when it shifts from the lower spinner to the upper two, no water comes out of the lower (so I do know that it is making the switch correctly), and water is flying out of the upper one. It is dribbling out of the middle, but not nearly enough to spin it. I was pressing hard against the rack, to simulate the door being shut.

Everything is most definitely clear. I've taken it all apart and inspected it.

The upper spinner is very light, there's almost nothing to it. I can imagine that if the motor was not pushing the water hard enough, there might still be enough force to spin it. The middle one, since it is bulkier, might not be able to with insufficient force.

Then again, the lower one seems to spin just fine when the water is directed to it. I'm about at the end of my rope here.

I've taken the water tube on the back off, inspected it, and there are no restrictions. Last night I took the bottom and middle spray arms off, and ran the washer with the door open. It looks as if a ton of water is coming through the opening that feeds the middle spray arm, but when I ran it again with the spray arm in place, it barely moves, or stops altogether.

There seem to be no restrictions in the spray arm, and it rotates freely by hand. Does it seem more likely to you that the spray arm is somehow compromised, or that the motor is not running as strongly as it should? Like I said, water is really pouring out of there, but I also have nothing to compare it to.

You were right, that was it. Thanks!