Service Manual

3-10
n
Whirlpool & Maytag Front-Load Dryers
COMPONENT TESTING
For Service Technician Use Only
TEST #2: Supply Connecons
This test assumes that proper voltage is present at the outlet,
and for U.S. installaons, a visual inspecon indicates that the
power cord is securely fastened to the terminal block (electric
dryer) or wire harness connecon (gas dryer).
ELECTRIC DRYER (U.S. Installations):
1. Unplug dryer or disconnect power.
2. Remove the cover plate from the top right corner of the
back of the dryer. See gure 1.
3$*(
FOR SERVICE TECHNICIAN’S USE ONLY
DO NOT REMOVE OR DESTROY
TEST #2: Supply Connections
This test assumes that proper voltage is present
at the outlet, and for U.S. installations, a visual
inspection indicates that the power cord is
securely fastened to the terminal block (electric
dryer) or wire harness connection (gas dryer).
ELECTRIC DRYER (U.S. Installations):
1. Unplug dryer or disconnect power.
2. Remove the cover plate from the top right
corner of the back of the dryer. See figure 3.
3. With an ohmmeter, check for continuity
between the neutral (N) terminal of the plug
and the center contact on the terminal block.
See figure 4a.
¾If there is no continuity, replace the power
cord and test the dryer.
¾If there is continuity, go to step 4.
4. In a similar way, check which terminal of
the plug is connected to the left-most contact
on the terminal block and make a note of
it. This will be L1 (black wire) in the wiring
diagram. See figure 4a.
¾When this is found, go to step 5.
¾If neither of the plug terminals have
continuity with the left-most contact of the
terminal block, replace the power cord and
retest dryer.
5. Access the machine electronics without
disconnecting any wiring to the ACU (see
Dryer Disassembly Instructions, page 24).
Figure 3 - Remove the cover plate
(appearance may vary).
COM
N
L1
Figure 4a - Plug-to-terminal connections
for electric dryer.
Power Cord
Plug
Terminal Block
Cover Plate
Remove Screw
6. ACU +5VDC – With voltmeter set to DC,
unplug connector J2 from the ACU and
connect black probe to ACU J2-4 (ground)
and red probe to J2-2 (+5V DC). Plug in
dryer or reconnect power.
¾If +5VDC is present, unplug dryer or
disconnect power and go to step 9.
¾If +5VDC is not present, go to step 7.
7. Unplug dryer or disconnect power. Unplug
J14 from the ACU. Plug in dryer or reconnect
power and repeat step 6.
¾If +5VDC returns, one of the thermistors
has shorted. To diagnose thermistors,
see TEST #4a, page 17.
¾If +5VDC is not present, go to step 8.
8. Unplug dryer or disconnect power.
Reconnect J14 to the ACU and unplug J2 from
the ACU. Plug in dryer or reconnect power and
repeat step 6. Perform voltage check inside
header J2 on ACU, between pins 2 & 4—DO
NOT SHORT PINS TOGETHER.
¾If +5VDC is still missing, unplug dryer or
disconnect power and replace the ACU.
¾If +5VDC returns, unplug dryer or
disconnect power and check harnesses
and connections between the ACU and
HMI. If acceptable, replace the HMI.
9. ACU +12.7VDC – with voltmeter set
to DC, connect black probe to ACU J2-4
(ground) and red probe to J2-1 (+12.7VDC).
Plug in dryer or reconnect power.
¾If +12.7VDC is present, go to step 11.
¾If +12.7VDC is not present, go to step 10.
10.Unplug dryer or disconnect power. Unplug
connector J2 from the ACU. Perform voltage
check inside header J2 on ACU, between pins
1 & 4—DO NOT SHORT PINS TOGETHER.
¾If +12.7VDC is still missing, unplug dryer
or disconnect power and replace the ACU.
¾If +12.7VDC returns, unplug dryer or
disconnect power and check harnesses
and connections between the ACU and
HMI. If acceptable, replace the HMI.
11.Unplug dryer or disconnect power.
12. Reassemble all parts and panels.
13. Perform steps under “Service Test Mode,”
page 6, to verify repair.
Figure 1 - Remove the cover plate (appearance may vary).
3. With an ohmmeter, check for connuity between the
neutral (N) terminal of the plug and the center contact on
the terminal block. See gure 2.
¾ If there is no connuity, replace the power cord and
test the dryer.
¾ If there is connuity, go to step 4.
4. In a similar way, check which terminal of the plug is
connected to the le-most contact on the terminal block
and make a note of it. This will be L1 (black wire) in the
wiring diagram. See gure 2.
¾ When this is found, go to step 5.
¾ If neither of the plug terminals have connuity with the
le-most contact of the terminal block, replace the
power cord and retest dryer.
3$*(
FOR SERVICE TECHNICIAN’S USE ONLY
DO NOT REMOVE OR DESTROY
¾If +5VDC is still missing, unplug dryer or
disconnect power and replace the CCU.
¾If +5VDC returns, unplug dryer or
disconnect power and check harnesses
and connections between the CCU and user
interface (UI). If acceptable, replace the UI.
8. CCU +12VDC – with voltmeter set to DC,
connect black probe to CCU P5-3 (ground)
and red probe to P5-8 (+12VDC). Plug in
dryer or reconnect power.
¾If +12VDC is present, go to step 9.
¾If +12VDC is not present, unplug dryer
or disconnect power and replace the CCU.
9. Unplug dryer or disconnect power.
10. Reassemble all parts and panels.
11. Perform steps under “Install Diagnostics”,
page 6, to verify repair.
TEST #2: Supply Connections
This test assumes that proper voltage is present
at the outlet, and a visual inspection indicates
that the power cord is securely fastened to the
terminal block.
U.S. Installations:
1. Unplug dryer or disconnect power.
2. Remove the cover plate from the top right
corner of the back of the dryer. See figure 3.
3. With an ohmmeter, check for continuity
between the neutral (N) terminal of the plug
and the center contact on the terminal block.
See figure 4a.
¾If there is no continuity, replace the power
cord and test the dryer.
¾If there is continuity, go to step 4.
4. In a similar way, check which terminal of
the plug is connected to the left-most contact
on the terminal block and make a note of
it. This will be L1 (black wire) in the wiring
diagram. See figure 4a.
¾When this is found, go to step 5.
¾If neither of the plug terminals have
continuity with the left-most contact of the
terminal block, replace the power cord and
retest dryer.
5. Access the machine electronics without
disconnecting any wiring to the CCU.
6. With an ohmmeter, check for continuity
between the L1 terminal of the plug (found
in step 4) and P9-2 (black wire) on the CCU.
¾If there is continuity, go to step 7.
¾If there is no continuity, check that wires to
the terminal block are mechanically secure.
If so, replace the main wire harness and
test the dryer.
7. Check for continuity between the neutral
(N) terminal of the plug and P8-3 (white wire)
on the CCU.
¾If there is continuity, go to step 8.
¾If there is no continuity, and the mechanical
connections of the wire are secure, replace
the main wire harness.
8. Visually check that ALL connectors are
fully inserted into the CCU.
9. Visually check that ALL connectors are
fully inserted into the UI.
10. Reassemble all parts and panels.
11. Plug in dryer or reconnect power.
12. Perform steps under “Install Diagnostics”,
page 6, to verify repair.
Canadian Installations:
1. Unplug dryer or disconnect power.
2. Remove the cover plate from the top right
corner of the back of the dryer. See figure 3.
3. Access the machine electronics without
disconnecting any wiring to the CCU.
4. With an ohmmeter, check the continuity
from L1 and N plug terminals of the power
cord to the terminals for L1 and N on the
CCU. See figure 4b, page 12.
Figure 3 - Remove the cover plate.
COM
N
L1
Figure 4a - Plug-to-terminal connections
for electric dryer.
Power Cord
Plug
Terminal Block
Cover Plate
Remove Screw
Figure 2 - Plug-to-terminal connections for electric dryer.
5. Remove top panel. Access the machine electronics
without disconnecng any wiring to the ACU.
6. With an ohmmeter, check for connuity between the L1
terminal of the plug (found in step 4) and J9-2 (black wire)
on the ACU.
¾ If there is connuity, go to step 7.
¾ If there is no connuity, check that wires to the
terminal block are mechanically secure. If so, replace
the main wire harness and test the dryer.
7. Check for connuity between the neutral (N) terminal of
the plug and J8-3 (white wire) on the ACU.
¾ If there is connuity, go to step 8.
¾ If there is no connuity, and the mechanical
connecons of the wire are secure, replace the main
wire harness.
8. Visually check that ALL connectors are fully inserted into
the ACU.
9. Visually check that ALL connectors are fully inserted into
the HMI.
10. Reassemble all parts and panels.
11. Plug in dryer or reconnect power.
12. Perform steps under “Service Diagnosc Mode”, page 2-4,
to verify repair.
ELECTRIC DRYER (Canadian Installations):
1. Unplug dryer or disconnect power.
2. Remove the cover plate from the top right corner of the
back of the dryer. See gure 1.
3. Remove top panel. Access the machine electronics
without disconnecng any wiring to the ACU.
4. With an ohmmeter, check the connuity from L1 and N
plug terminals of the power cord to the terminals for L1
and N on the ACU. See gure 3, page 3-11.
¾ If connuity exists for both connecons, go to step 6.
¾ If an open circuit is found, check the integrity of the
connecons of the power cord to the harness in the
dryer; harness to the ACU; and the integrity of the
power cord itself.
WARNING
Electrical Shock Hazard
Disconnect power before servicing.
Failure to do so can result in death or
electrical shock.
Replace all parts and panels before operating.