For Service Technician Use Only
COMPONENT TESTING (Cont.)
Whirlpool
®
and KitchenAid
®
Filtration and Maytag
®
24" Microfiltration Dishwashers
n
3-17
Wash Motor RIF
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 and Capacitor
n
Control Board
n
Wash motor fuse (Some models)
Test Procedure
1.
Check the tube 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 Diagnostics Cycle. The following steps
assume that this step was unsuccessful.
3.
Unplug dishwasher or disconnect power.
4.
Remove toe and outer door panels to access control board.
5.
Unplug connector P5 from control board.
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.
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.
Strip Circuit - Wash Motor RIF
7.
Check the motor fuse (Some models). Using an ohmmeter,
measure the resistance between P5-1 and P5-4 on the
control.
¾
If the resistance is less than 3 ohms, fuse is good. Go to
step 8.
¾
If the resistance is greater than 3 ohms, replace the
control.
8.
Reconnect P5 to control board.
9.
Set voltmeter to AC and connect leads to test-pads.
10.
P5-1 and P5-2 on the control board. Plug in dishwasher or
reconnect power.
11.
Start the Diagnostics Cycle and at the proper interval
measure for AC out of the control board between P5-1 and
P5-2 (Refer to Wash Motor Strip Circuit below).
¾
If no AC voltage is measured, replace the control board
and retest.
¾
If 120 VAC is measured and wash motor is running, go to
step 12.
¾
If 120 VAC is measured and wash motor is not running, go
to step 10.
12.
Test the wash motor capacitor.
NOTE
: A faulty capacitor may cause the motor to "hum", not
start, or start slowly.
A. Discharge the capacitor by touching the leads of a
20,000 ohms resistor to the two terminals.
B. Disconnect the wires from the capacitor terminals.
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.
¾
If the capacitor is either shorted or open, replace
capacitor and retest.
¾
If the preceding steps did not correct the wash motor
problem, replace the control board.
13.
Unplug dishwasher or disconnect power.
14.
Reassemble all parts and panels.
15.
Plug in dishwasher or reconnect power and run Diagnostics
Cycle to verify repair.
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.
BK
TURQ
(LBU)
Electronic Control
P5-1
Pin 3
K502
Motor N Relay
(Also see Door
Switch Circuit)
WH
P5-2
P4-4
Sense Resistor
or Jumper
0
Ω
N
L1
V
Y
Y
Pin 2 AUX
Winding
10 Ω - 12 Ω
CAP
23.5
μ
F
Run
Winding
7 Ω - 9 Ω
at 25°C
Motor and Capacitor
(Wash Pump)
120 V
, 60 Hz, 90 W (No load)
TURQ
(LBU)
Electronic Control
N.O.
Fuse
F501
(Some models)
N.O.
K503
Pilot L1 Relay
(Also see Door
Switch Circuit)
P4-1
210 W (Full load)