Whirlpool Maytag W11416805 Technical Manual page 30

COMPONENT TESTING (Cont.)
High Limit Thermostat
Flame
Sensor
Thermal Fuse
Figure 11 - Thermal components, gas dryer,
viewed from front.
4. Visually check the wire connections to the thermal cut-
off, high limit thermostat, and heater. If the connections
look good, check for continuity across each of these
components. Refer to
n Replace the heater if it is electrically open.
n Replace both the thermal cut-off and the high limit
thermostat if either the thermal cut-off or the high limit
thermostat is electrically open.
5. If no open circuit is detected, remove the J14 connector
from the ACU and measure the outlet thermistor resistance
between J14-3 and J14-6 at the connector. Refer to
Thermistor Resistance" table for temperatures and their
associated values.
n If the resistance corresponds to the temperature, the
outlet thermistor is good. Go to step 6.
n If the thermistor resistance does not agree with the
table, replace the outlet thermistor.
6. If the preceding steps did not correct the problem and L1
and L2 were both detected, replace the ACU. If L2 was not
detected, suspect the centrifugal switch before replacing
the ACU.
7. Reassemble all parts and panels.
8. Plug in dryer or reconnect power.
9. Perform steps under "Service Test Mode", to verify repair.
Gas Dryer Only:
1. Verify the gas supply to the dryer is turned on.
2. Unplug dryer or disconnect power.
3. For Gas 29" only, perform
thermal fuse is OK, go to step 4.
4. Perform Test #4c: Thermal
OK, go to step 5.
5. Locate the high limit thermostat (see figure 11). Measure
the continuity through it by connecting the meter probes to
the red and black wire terminals.
n If there is an open circuit, replace both the high limit
thermostat and the thermal cut-off.
n Otherwise, go to step 6.
3-8 n Whirlpool® and Maytag® Dryer
For Service Technician Use Only
Thermal
Cut-Off
Outlet
Thermistor
strip circuits.
Test #4b: Thermal Fuse. If the
Cut-Off. If the thermal cut-off is
6. Perform
Test #4d: Gas
step 7.
7. If the preceding steps did not correct the problem, suspect
the centrifugal switch before replacing the ACU.
8. Reassemble all parts and panels.
9. Plug in dryer or reconnect power.
10. Perform steps under "Service Test Mode", to verify repair.
Heat will not shut off:
All Dryers:
1. Unplug dryer or disconnect power.
2. Remove console to access the machine electronics.
3. Remove connector J14 from the ACU and measure the
resistance between J14-3 and J14-6 at the connector. Refer
to "Outlet Thermistor
their associated values.
n If the resistance corresponds to the temperature, the
outlet thermistor is good.
n If the thermistor resistance does not agree with the
table, replace the outlet thermistor.
4. Check heater coil(s) for a short to ground (usually inside the
heater box). Repair or replace if necessary.
5. Plug in dryer or reconnect power.
6. Run an "AIR" only timed dry cycle (no heat). Check heater
relay output on ACU. Unplug dryer or disconnect power.
With a voltmeter set to AC, connect voltmeter to terminals
1 and 2 of heater relay. Plug in dryer or reconnect power.
Measure the voltage across terminals 1 and 2 of heater
relay.
n If voltage is present (~240 VAC for electric, ~120 VAC for
gas), the relay is open and working normally.
n If little or no voltage is present, the relay is closed and
"Outlet
heater is activated. Unplug dryer or disconnect power
and replace the ACU.
7. Unplug dryer or disconnect power.
8. Reassemble all parts and panels.
9. Plug in dryer or reconnect power.
10. Perform steps under "Service Test Mode", to verify repair.
Test #4a: Thermistors
NOTE: Refer to
temperature thermistors.
Outlet (Exhaust) Thermistor
The ACU monitors the exhaust temperature using the outlet
thermistor, and cycles the heater relay on and off to maintain the
desired temperature.
NOTE: Begin with an empty dryer and a clean lint screen.
1. Unplug dryer or disconnect power.
2. Remove console to access the machine electronics.
3. Remove connector J14 from the ACU and measure the
resistance between J14-3 and J14-6 at the connector. The
following table gives temperatures and their associated
resistance values.
NOTE: All thermistor resistance measurements must be made
while dryer is unplugged and connector removed from ACU.
Valve. If the gas valve is OK, go to
Resistance" for temperatures and
strip circuits to diagnose outlet and inlet