Whirlpool WED90HEFC W10240504 - Page 19

FOR SERVICE TECHNICIAN'S USE ONLY 4. Check P14-1 and P14-2 to dryer cabinet ground. If either pin indicates continuity to ground (short), replace wiring harness; otherwise, proceed to step 5. 5. If the preceding steps did not correct the problem, replace the CCU. TEST #4b: Thermal Fuse ELECTRIC DRYER: The thermal fuse is wired in series with the dryer drive motor. GAS DRYER: The thermal fuse is wired in series with the dryer gas valve. ALL DRYERS: 1. Unplug dryer or disconnect power. 2. Access the thermal fuse by removing the front panel. See Dryer Disassembly Instructions, page 24. 3. Using an ohmmeter, check the continuity across the thermal fuse.  If the ohmmeter indicates an open circuit, replace the thermal fuse. TEST #4c: Thermal Cut-Off If the dryer does not produce heat, check the status of the thermal cut-off. 1. Unplug dryer or disconnect power. 2. Access the thermal cut-off by removing the front panel. See Dryer Disassembly Instructions, page 24. 3. Using an ohmmeter, check the continuity across the thermal cut-off. See figures 10 and 11, page 16, for location. 4. If the ohmmeter indicates an open circuit, perform the following: ALL DRYERS: Replace both the thermal cut-off and high limit thermostat. In addition, check for blocked or improper exhaust system, and, on electric dryers, for heat element malfunction. TEST #4d: Gas Valve (Gas Dryer) 1. Unplug dryer or disconnect power. 2. Access the gas valve by removing the front panel. See Dryer Disassembly Instructions, page 24. 3. Use an ohmmeter to determine if a gas valve coil has malfunctioned. Remove harness plugs. Measure resistance across the terminals (see figure 12). Readings should match those shown in the following chart; if not, replace coils. GAS VALVE RESISTANCE Terminals 1 to 2 Resistance in ohms 1400 ± 70 1 to 3 570 ± 28.5 4 to 5 1300 ± 65 Pin 1 - Black Pin 2 - Blue Pin 3 - White Pin 4 - Blue Pin 5 - White Figure 12 - Measuring gas valve resistance. 4. Disconnect the ignitor plug from the burner. Using an ohmmeter, measure the resistance across the ignitor's 2-pin connector. Resistance should be 50-500 Ω.  If resistance readings are outside the range or open, replace the ignitor.  If resistance readings are within range, reconnect the ignitor plug and continue to step 5. 5. Disconnect the wires going to the flame sensor terminals. Using an ohmmeter, measure across the two sensor terminals for continuity.  If there is continuity, reconnect the sensor wires and continue to step 6.  If the reading is open, the flame sensor needs replacing. 6. Reassemble front panel before reconnecting power. 7. Plug in dryer or reconnect power. 8. Run a high-temp TIMED DRY cycle of at least 2 minutes in duration. 9. Watch the ignitor for a couple of minutes through the "peek window" in the side. If the ignitor stays red hot and the gas does not come out and ignite, the flame sensor needs replacing. NOTE: If ignitor does not come on, line voltage may not be present at the gas burner. The motor centrifugal switch may be suspect. DO NOT REMOVE OR DESTROY PAGE 19