Several weeks back we noticed that dishes on the bottom rack of our dishwasher weren't getting clean. After looking online I did some visual testing and found that the lower wash arm on my dishwasher wasn't rotating.

1) I removed the arm and looked at it, all the gearing looked good and if I turned it by hand, it rotated as expected.

2) I then made a sharpie mark on the gear coming from the washarm motor (W10843811) and ran the dishwasher again. Even without the wash arm, the shaft was not turning.

3) I then ran a diagnostic cycle with immediately flashed F9E4 before even starting, then ran and after the cycle flashed F-E-

Putting this all together I ordered a new motor W10843811 which arrived yesterday. Today I put the motor in. When doing I noted that everything was dry, no corrosion, connectors all looked good etc.

Put it all back together and lo and behold. Same exact issue. Shaft doesn't turn (and therefore arm doesn't) diagnostic flashes F9E4 immediately upon start and then F-E- after running.

Just to be sure I removed the gray cover that goes on top of the shaft and rotated it by hand and it turns easily and without any binding.

I'm unclear what the next step is. The manual appears to say this is either the control board or a fuse.

Here's what's really confusing. From looking at everything it appears to me that the motor controls both the diverter (diffuser?) disk and the lower wash arm. If it isn't turning how is it that the top rack is getting water and cleaning things up top well?

Argh. Any advice would be appreciated.

Edited by user Sunday, October 17, 2021 4:54:02 PM(UTC)  | Reason: Spelling corrections