Whirlpool M-17 Technical Manual page 58

COMPONENT TESTING (Cont.)
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.
Drain Motor with RIF or SSM
This test will check the wiring to the drain motor and the drain
motor itself. The following items are part of the drain motor
circuit:
n Harness/Connection
n Drain Motor
n Control Board
Test Procedure
1. Verify that drain hose or drain path is not obstructed. Check
for blockage from sump check valve to customer's plumbing.
Check for plugged garbage disposal or disposal plug not
knocked out. Check drain loop, stuck check valve, or for
plugged hoses. Repair as needed.
2. Check the drain motor and electrical connections by
performing the Service Diagnostics Cycle. The following steps
assume that this step was unsuccessful.
3. Are all the loads controlled by TRIAC not working?
¾ YES - check for open door switch, TRIAC fuse, or pilot
relay.
¾ NO - just the drain motor. Go to step 4.
4. Unplug dishwasher or disconnect power.
5. Remove toe and outer door panels to access control board.
Strip Circuit -Drain Motor with RIF or SSM
L1
BK
3-20 Whirlpool and KitchenAid
n
®
For Service Technician Use Only
P5 Pins 1 and 4 to test fuse
N.O.
P4-1
K503
Pilot L1 Relay
Fuse
(Also see Door
F500
Switch Circuit)
Electronic Control
Filtration and Maytag
®
6. Unplug connector P5 from control board.
7. Check the drain motor using an ohmmeter, measure the
resistance between P5-3 and P5-4.
¾ If the resistance is between 27-33 ohms, the drain motor
and harness are good. Go to step 8.
¾ If outside the range, replace the drain motor.
¾ If an open circuit is detected, check connections and
harness continuity between control and drain motor. If
good, replace the drain motor.
8. Reconnect P5 to control board.
9. Set voltmeter to AC and connect leads to test-pads P5-3 and
P5-4 on the control board. Plug in dishwasher or reconnect
power.
10. Start the Diagnostics Cycle and at the proper interval
measure for AC out of the control board between P5-3 and
P5-4 (Refer to Drain Motor Strip Circuit below).
IMPORTANT: The Drain Motor must be connected to the
control board to measure voltage accurately.
¾ If no AC voltage is measured, replace the control board
and retest.
¾ If 120 VAC is measured and drain motor is running, go to
step 11.
11. Unplug dishwasher or disconnect power.
12. Reassemble all parts and panels.
13. Plug in dishwasher or reconnect power and run Diagnostics
Cycle to verify repair.
BR
P5-4
Pin 1
Drain Motor
27 Ω - 33 Ω
120 V, 60 Hz, 45 W
24" Microfiltration Dishwashers
®
BR
P4-4
P5-3
Pin 3
TRIAC
Electronic Control
N
WH