Some friends asked me to look at their dishwasher. Apparently it's had a small leak for some time, and they used a towel on the floor to soak up water while it's running. Now the soap cup won't open.

I got the model number from them, but haven't physically been over to see the unit. I'm trying to do my homework ahead of time because my time is limited.

The exploded view shows a wax motor as the actuator for the soap cup. Can this wax motor be checked with an ohmmeter? Can I apply a voltage to actuate the motor and verify operation? If so, does it see 120V or is it stepped down?

On the leak issue, is there a common reason on this model for the leak? I'm just trying to figure out in advance if there's a particular seal I should buy and have ready to install.

Any tips or tricks to attacking these problems are welcome. Thanks in advance.

Mark in MA

Here's the part number. If you click on the larger of the photos, you can read 120/240VAC. So if you disconnect it from the D/W wires, and apply a test cord to it, You can observe its action. It's slow. Don't expect it to "spring" into action.
Part number: AP4110779

An update:
The long-term leak that they were experiencing was actually a missing grommet sealing off the latch mechanism which opens the soap dispenser. This leak eventually took out the wax motor that opens the soap cup. Wax motor and grommet are on order from this site. I'll update when the fix is installed and confirmed.

Thanks for the help

Mark