Replacement dispenser for KUDA03CTBS3 not working

Dishwasher Repair
1

Brand: Kitchen-Aid
Model Number: KUDA03CTBS3
Main Symptom: Detergent dispenser does not open during wash
What happens & when:

Error Code (if any):
Parts or tests already tried: WPW10195175
Photos / video link:

Bought dishwasher September 2008 - Replaced control board July 2019.

The old dispenser stopped opening in the wash cycle last month. Installed replacement part, Order #17316818, no change.

2

Since you already replaced the dispenser and nothing changed, I would not replace another dispenser. The next thing to determine is whether the control is actually sending power to it.

One parts listing does show WPW10195175 as a compatible replacement dispenser for KUDA03CTBS3, although another model-specific diagram lists an earlier/superseded dispenser number.

Quickest test — check voltage at the dispenser

You’ll need a multimeter. This is a live-voltage test, so use caution around the exposed door wiring.

  1. Turn the dishwasher breaker OFF.
  2. Remove the Torx screws around the inside perimeter of the door.
  3. Separate/support the outer panel enough to access the back of the detergent dispenser.
  4. Locate the 2-wire electrical connector going to the dispenser.
  5. Leave the dispenser connected and back-probe those two wires with your meter.
  6. Set the meter to AC volts, 200 V range or auto-ranging.
  7. Reassemble/support the door sufficiently that it can be safely latched.
  8. Start a Normal wash cycle.
  9. Watch the meter during the first several minutes of the wash.

The dispenser should receive a brief line-voltage pulse when the control commands the detergent door to release. Whirlpool/KitchenAid designs of this type operate the dispenser from approximately 120 VAC.

What the reading tells us

If you get about 120 VAC briefly but the door doesn’t open: the problem is at the new dispenser, its connector, or mechanically at the dispenser door. Before condemning it, make sure the dispenser lid opens freely by hand and isn’t contacting a rack or oversized dish.

If you get 0 VAC: that’s the important result. Since you’ve already installed a new dispenser, I’d move upstream and check the door wiring harness and control board.

With power disconnected, inspect the harness where it bends near the bottom of the dishwasher door. After almost 18 years of opening and closing, a broken conductor inside the insulation is quite possible. Look especially for a wire that stretches, feels unusually soft, or has damaged insulation.

You can also disconnect the dispenser and control connections and check the dispenser circuit end-to-end for continuity. You’re looking for essentially 0 Ω/continuity through each wire, not OL.

If the wiring checks good

Then I would suspect the electronic control.

Your model uses electronic control WPW10084141 according to the model-specific parts information. Since yours was replaced in 2019, it’s entirely possible that the dispenser output on that board has failed even though the rest of the dishwasher operates normally.

The sequence I’d use is:

New dispenser → check for 120 VAC command → check door harness → control board.

I would not buy the control board yet. That live-voltage test at the dispenser will separate a dispenser/mechanical problem from a wiring/control problem very quickly.

If you tell me what voltage you get across the two dispenser wires while it’s running, I can take you to the next exact test.