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Auxiliary Blower Motor Operates Continuously

NOTE: Auxiliary blower motor medium speed relay has two Red wires. Red wire, direct feed from convenience center, is hot at all times. The other Red wire is a switching wire to both auxiliary A/C-heater control assemblies.
  1. Perform BLOWER CONTROLS SYSTEM CHECK . Go to next step.
  2. Remove auxiliary blower relays one at a time. Note when blower motor stops and which relay was removed. If blower motor stops, go to next step. If blower motor does not stop after all relays are removed, go to step  4.
  3. Replace suspect relay. Go to BLOWER CONTROLS SYSTEM CHECK .
  4. With all relays removed, use a DVOM to measure voltage between ground and auxiliary blower motor high speed relay cavity terminal No. 4 (Yellow wire). See WIRING DIAGRAMS . If reading is one volt or less, go to BLOWER CONTROLS SYSTEM CHECK . If reading is greater than one volt, go to next step.
  5. Repair short to battery voltage in Yellow wire between auxiliary blower motor, auxiliary blower motor resistor, and auxiliary blower motor high speed relay. Go to BLOWER CONTROLS SYSTEM CHECK .
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