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Auxiliary Blower Motor Inoperative

  1. Perform BLOWER CONTROLS SYSTEM CHECK . Go to next step.
  2. Disconnect front auxiliary A/C-heater control assembly. Use a DVOM to check for continuity between auxiliary blower switch connector terminal "B" (Black wire) and ground. See WIRING DIAGRAMS . If continuity is indicated, go to step  4. If continuity is not indicated, go to next step.
  3. Repair open in Black wire between auxiliary blower switch connector terminal "B" and ground. Go to BLOWER CONTROLS SYSTEM CHECK .
  4. Use a DVOM with negative lead connected to terminal "B" of front auxiliary A/C-heater control assembly and check for continuity to remaining terminals on A/C-heater control assembly. Rotate switch through all blower speeds. See AUXILIARY A/C-HEATER CONTROL ASSEMBLY TEST  table. If continuity is as specified, go to step  6. If continuity is not as specified, go to next step .
    AUXILIARY A/C-HEATER CONTROL ASSEMBLY TEST

    Switch Position Continuity Between Terminals
    Off (1)(2) None
    Low (1) B & C; (2) F & C
    Medium (1) B & E; (2) F & E
    High (1) B & D; (2) F & D
    Rear (1) B & F
    (1) Front auxiliary A/C-heater control assembly.
    (2) Rear auxiliary A/C-heater control assembly.
  5. Replace front auxiliary A/C-heater control assembly. See AUXILIARY A/C-HEATER CONTROL ASSEMBLIES  under REMOVAL & INSTALLATION. Go to BLOWER CONTROLS SYSTEM CHECK .
  6. Disconnect auxiliary blower motor resistor (located on top of auxiliary heater unit, near right rear wheelwell). Disconnect auxiliary blower motor connector. Use a DVOM to check for continuity in Yellow wire between auxiliary blower motor resistor connector terminal "B" and auxiliary blower motor connector terminal "A". If continuity is indicated, go to step  8. If continuity is not indicated, go to next step.
  7. Repair open in Yellow wire between auxiliary blower motor resistor and auxiliary blower motor. Go to BLOWER CONTROLS SYSTEM CHECK .
  8. Use a DVOM to check for continuity between ground and auxiliary blower motor connector terminal "B" (Black wire). If continuity is indicated, go to next step. If continuity is not indicated, go to step  10.
  9. Replace auxiliary blower motor. See AUXILIARY BLOWER MOTOR & FAN  under REMOVAL & INSTALLATION. Go to BLOWER CONTROLS SYSTEM CHECK .
  10. Repair open in Black wire between auxiliary blower motor and ground. Go to BLOWER CONTROLS SYSTEM CHECK .
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