Wash Motor - KitchenAid KMTM704E Series Technical Education

TESTING
DANGER
Electrical Shock Hazard
Only authorized technicians should perform
diagnostic voltage measurements.
After performing voltage measurements,
disconnect power before servicing.
Failure to follow these instructions can result in
death or electrical shock.
-4 -3 -2 -1 -2 -1

Wash Motor

P5
P4
This test will check the wiring to the wash motor and the wash
motor itself. The following items are part of the wash motor
circuit.
n Harness/Connection
n Wash Motor & Capacitor
n Control Board
Test Procedure
1. Check the tub and sump for anything that may be
impeding water flow. Inspect and if necessary clean the
coarse-filter system. Also, inspect spray arm water nozzles
and clean if needed.
2. Check the wash motor and electrical connections by
performing the Service Diagnostic Cycle. The following
steps assume that this step was unsuccessful.
3. Unplug dishwasher or disconnect power.
13V
4. Remove toe and access panels to access control board. N.O.
V V
5. Unplug connector P5 from control board.
P9-6 P9-5
Door
Switch
P10-4
Electronic Control
Strip Circuit – Wash Motor
Motor Power
L1
BK
KitchenAid 2015 Microfiltration Dishwashers
n
6-14
For Service Technician Use Only
Control Pinout
(Top)
W2
P5
P6
-9 -1
-1 -6
P7
P6
BR
BU
Dishwasher Strip Circuits
(To Heater)
N.O.
Door
K1
Switch
Heater (N) Relay
Sensing
Input
Ref
N.O.
P4-2
K2
Pilot L1 Relay
(Also see Door
Switch Circuit)
Electronic Control
Electronic Control
6. Check the wash motor—using an ohmmeter, measure the
resistance between P5-1 and P5-2.
¾ If the resistance is between 10-15 ohms, the wash
motor and harness are good. Go to step 7.
Ω of F9 Triac Fuse
¾ If outside the range, replace the wash motor.
¾ If an open circuit is detected, check connections and
harness continuity between control and wash motor. If
good, replace the wash motor.
7. Reconnect P5 to control board.
P7
8. Set voltmeter to AC and connect leads to test-pads
P8 P9
P5-1 & P5-2 on the control board. Plug in dishwasher or
reconnect power.
9. Start the Diagnostic Cycle and at the proper interval
measure for AC out of the control between P5-1 & P5-2.
(Refer to Wash Motor Strip Circuit below.)
¾ If no AC voltage is measured, replace the control board
and retest.
-6 -1
-6 -1 -5 -6
¾ If 120 VAC is measured and wash motor is running, go
to step 12.
P8 P9
¾ If 120 VAC is measured and wash motor is not running,
RD V
go to step 10.
10. Test the wash motor capacitor. NOTE: A faulty capacitor
may cause the motor to "hum," not start, or start slowly.
Unplug dishwasher or disconnect power.
I
a. Discharge the capacitor by touching the leads of a
20,000 Ω resistor to the two terminals.
Perform resistance checks. To check resistance of a comp
I
b. Disconnect the wires from the capacitor terminals.
disconnect harness leads first.
c. With an ohmmeter, measure across the terminals and
note reading.
¾ If a steady increase in resistance is noted, capacitor is
good. Replace wash motor assembly and retest.
(To Wash Motor,
Vent, and Triac Loads)
¾ If the capacitor is either shorted or open, replace
capacitor. and retest.
N.O.
11. If the preceding steps did not correct the wash motor
problem, replace the control board.
K2
Pilot (L1) Relay
12. Unplug dishwasher or disconnect power.
13. Reassemble all parts and panels.
14. Plug in dishwasher or reconnect power and run Diagnostic
Cycle to verify repair.
Micro Pin Micro Pin
Electronic Control
Run
Winding
3Ω - 7Ω
TURQ
(LBU)
V
P5-2
Pin 2
AUX
Y
Winding
6Ω - 10Ω
Motor and Capacitor
(Wash Pump)
120V, 60 Hz, 190W typical
N
P10 P11
-1 -3 -5 -1 -2 -4 -6
-1 -3
P10 P11 P12
BR RD YL
(To Wash Motor)
(To Heater)
N.O.
K3
Motor (N) Relay
Heater (L1) Relay
Micro Pin
Sense Resistor
TURQ
(LBU)
N.O.
P5-1
K4
Pin 3
Motor N Relay
CAP
Y
(Also see Door
23.5 µF
Switch Circuit)
Electronic Control
YL Pin 1
P12
P13
(OWI)
P12 (Wide Out)
P13
N.O.
K4
Micro Pin
N
or Jumper
0Ω
WH
P4-1