19. | You have an open wire or bad terminal on either the ORANGE or VIOLET wire between connectors | Ð | Ð | 5 | ||
PL13 and PL3. Repair it or replace blower harness(es). | ||||||
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20. | Remove tape from door switch and turn power off at main disconnect. | Ð | Ð | 21 | ||
21. | Does blower wheel rub against blower housing? | 4 | 22 | Ð | ||
22. | Does blower wheel turn freely? |
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23. | Is blower wheel firmly mounted on motor shaft? | 25 | 4 | Ð | ||
→24. | Replace entire blower motor or blower control module attached to the blower motor. If you replace |
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the blower control module go to step 44. Always inspect failed motor for water damage. If present, | Ð | Ð | 4 | |||
| find source of water and fix. Check |
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25. | Disconnect jumper wire across R and W/W1 thermostat terminals. | Ð | Ð | 26 | ||
26. | Turn power back on. Depress door switch. Use a piece of tape to hold switch closed. Wait a few | Ð | Ð | 27 | ||
sec for self test before proceeding to next step. | ||||||
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27. | Do you have 120v between B1 and B2 on furnace control board? | 28 | 4 | Ð | ||
28. | Do you have 120v between BLACK and WHITE power leads at blower motor MTR2? | 30 | 29 | Ð | ||
29. | You have an open wire or bad terminal on either the BLACK or WHITE wire between furnace con- | Ð | Ð | 5 | ||
trol board and blower motor MTR2. | ||||||
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| Check blower ON/OFF line. To do this, connect a DC voltmeter across terminals |
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30. | and |
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voltage across RED and BLUE wires change between states as shown below? | 32 | 31 | Ð | |||
| · | State 1ÐOFF |
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| · | State 2ÐON (9.0 Ð 10.0 vdc) |
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| Disconnect PL3 from furnace control board and connect a DC voltmeter across terminals |
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| and |
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31. | 18 | 16 | Ð | |||
shown below? | ||||||
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| · | State 1ÐOFF |
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| · | State 2ÐON (11.0 Ð 12.0 vdc) |
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32. | Connect a DC voltmeter across RED (+) and BLUE |
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PONENT TEST by turning setup switch | 34 | 33 | Ð | |||
| the same DC voltages across RED and BLUE wires that you saw in Step 30? |
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33. | You have an open wire or bad terminal on either the RED or BLUE wire between connectors PL13 | Ð | Ð | 5 | ||
and PL3. Repair it or replace blower harness(es). | ||||||
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34. | Put setup switch | Ð | Ð | 35 | ||
| Check blower PW line. To do this, connect a DC voltmeter across terminals |
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35. | age across the RED and YELLOW wires change between states as shown below? | 37 | 36 | Ð | ||
· | State 1ÐOFF | |||||
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| · | State 2ÐLOW (2.5 Ð 3.0 vdc) |
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| · | State 3ÐHIGH (7.0 Ð 7.5 vdc) |
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| Disconnect PL3 from furnace control board and connect a DC voltmeter across terminals |
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| and |
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36. | 18 | 16 | Ð | |||
· | State 1ÐOFF | |||||
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| · | State 2ÐLOW (3.0 Ð 4.0 vdc) |
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| · | State 3ÐHIGH (9.0 Ð 10.0 vdc) |
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37. | Connect a DC voltmeter across RED (+) and YELLOW |
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COMPONENT TEST by turning setup switch | 18 | 38 | Ð | |||
| mately the same DC voltages across RED and YELLOW wires that you saw in Step 35? |
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38. | You have an open wire or bad terminal on either the RED or YELLOW wire between connectors | Ð | Ð | 5 | ||
PL13 and PL3. Repair it or replace blower harness(es). | ||||||
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39. | Go to page number indicated in Index for CLEANUP AND |
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persists on an intermittent basis, replace blower motor. If problem still persists on an intermittent | Ð | Ð | INDEX | |||
| basis after replacing blower motor, contact your distributor. |
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40. | Turn power off and remove blower access panel. Depress door switch. Use a piece of tape to hold | Ð | Ð | 41 | ||
switch closed. Wait a few sec for self test before proceeding to next step. | ||||||
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41. | Disconnect all thermostat leads from furnace control board. If blower motor is running, wait until it | Ð | Ð | 42 | ||
stops. | ||||||
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42. | Jumper R and G thermostat terminals. Observe operation of furnace for next 30 sec. | Ð | Ð | 43 | ||
| Approximately 20 sec after energizing G thermostat terminal, does blower motor pause briefly (less |
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43. | than1/2 sec?) | 3 | 18 | Ð | ||
Note:You can verify this pause using a | ||||||
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| motor MTR2. |
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14