Detergent Cup Not Opening (bimetal)

My Uncle, who is a retired appliance repair tech, suggested that I needed to replace the bimetal because of the problem described above. I will be darned if I can find the part listed on any diagrams. Any help would be greatly appreciated. Also, I have no idea how old the unit is as it was in place when I bought my home five years ago.
J

There is no bi-metal release in this model. Instead it has a wax motor. You can find the troubleshooting instructions in the Service manual.

Here are the breakdown diagrams and Replacement parts for MAYTAG DWU9920AAE | AppliancePartsPros.com

Gene.

Thank you for your time, Gene. I thought the wax motor may be the culprit, but was confused because the description seems to indicate that the wax motor is for the Rinse Aid as seen here:

Part Details - WHIRLPOOL Motor, wax (rinse disp.), part number: AP4110779

There is also a part listed as a Dual Wax Motor Conversion as seen here:

Part Details - WHIRLPOOL Dual wax motor conversion, part number: AP4009497

It would seem to me, having no knowledge about the workings of the dishwasher, that both of these operate the Rinse Aid. Am I wrong?

Thanks,
J

Do not rush with parts until you read the Service manual.

Gene.