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Test B: Air Delivery Improper - Cargo Van With Auxiliary HVAC

WARNING: This page is about a different car, the 2002 GMC Savana Special, 2002 GMC Savana Camper Special, 2002 GMC Savana, and 2002 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: For circuit reference, see CONNECTOR IDENTIFICATION  and/or WIRING DIAGRAMS  .
NOTE: Definition: Air does not flow correctly from the auxiliary air distribution outlets.
  1. If review of system operation has been performed, go to next step. If review of system operation has not been performed, see DESCRIPTION  and OPERATION  .
  2. Turn ignition on. Place auxiliary blower switch in the OFF position. If auxiliary blower motor is off, go to next step. If auxiliary blower motor is not off, go to TEST G: BLOWER MOTOR ALWAYS ON - WITH AUXILIARY HEATER or CARGO VAN WITH AUXILIARY HVAC  or TEST H: BLOWER MOTOR ALWAYS ON - PASSENGER VAN WITH AUXILIARY HVAC  .
  3. Turn parking lights on. Place instrument panel dimmer switch in the brightest position. Place auxiliary blower switch in each speed position. If auxiliary blower motor operates in any speed position, go to next step. If auxiliary blower motor does not operates in any speed position, go to TEST I: BLOWER MOTOR INOPERATIVE - AUXILIARY .
  4. If auxiliary blower motor operates in each speed position, go to next step If blower motor does not operate in each speed position, go to TEST J: BLOWER MOTOR MALFUNCTION - AUXILIARY .
  5. Place auxiliary blower switch in maximum speed position. Gradually change auxiliary mode switch from VENT position to FLOOR position. If air flows from the proper distribution outlets, check wire harness, vacuum harness and connections for intermittent conditions which could affect system. If air does not flow from the proper distribution outlets, go to next step.
  6. Turn ignition off. Disconnect auxiliary mode actuator. Turn ignition on. Using a test light connected to ground, probe ignition voltage 3 circuit (Brown Wire) of auxiliary mode actuator at connector terminal No. 10. See Fig 1. If test light illuminates, go to next step. If test light does not illuminate, go to step  15.
    Fig 1: Identifying Auxiliary Air Temperature Actuator Connector Terminals
    G00067640Courtesy of GENERAL MOTORS CORP.
  7. Check ground circuit of auxiliary mode actuator (Black wire) for an open or high resistance. See WIRING DIAGRAMS . If an open or high resistance was found, repair as necessary and go to step  18. If an open or high resistance was not found, go to next step.
  8. Using a DVOM, measure voltage at auxiliary mode actuator connector between terminals No. 7 and 8. See Fig 1. Gradually change auxiliary mode switch from VENT position to FLOOR position. If measured voltage continuously increases and decreases between zero volts in VENT position to 12 volts in FLOOR position, go to step  12. If measured voltage does not continuously increase and decrease zero-12 volts from VENT position to FLOOR position, go to next step.
  9. Check auxiliary mode door control circuit (Light Blue wire) of auxiliary mode actuator for an open, high resistance, short to ground, or short to voltage. See WIRING DIAGRAMS . If a circuit problem was found, repair as necessary and go to step  18. If a circuit problem was not found, go to next step.
  10. Check ignition 3 voltage circuit (Brown wire) of front auxiliary HVAC control assembly for an open or high resistance. See WIRING DIAGRAMS . If an open or high resistance was found, repair as necessary and go to step  18. If an open or high resistance was not found, go to next step.
  11. Check front auxiliary HVAC control assembly ground circuit (Black wire) for an open or high resistance. See WIRING DIAGRAMS . If an open or high resistance was found, repair as necessary and go to step  18. If an open or high resistance was not found, go to step  14.
  12. Check auxiliary mode actuator and door for proper mounting. Check for broken or binding linkage, or an obstruction preventing door from operating within it's full range. If an actuator or door condition was found, repair as necessary and go to step  18. If an actuator or door condition was not found, go to next step.
  13. Check for poor connections at auxiliary mode actuator harness connector. If a poor connection was found, repair as necessary and go to step  18. If a poor connection was not found, go to step  16.
  14. Check harness connector at front auxiliary HVAC control assembly for poor connections. If a poor connection was found, repair as necessary and go to step  18. If a poor connection was not found, go to step  17.
  15. Repair ignition 3 voltage circuit (Brown wire) of auxiliary mode actuator. See WIRING DIAGRAMS . If repair is complete, go to step  18.
  16. Replace auxiliary mode actuator. See ACTUATORS  under REMOVAL & INSTALLATION. After repairs are complete, go to step  18.
  17. Replace front auxiliary HVAC control assembly. See FRONT AUXILIARY HVAC CONTROL ASSEMBLY  under REMOVAL & INSTALLATION. If replacement is complete, go to next step.
  18. Operate system to verify repair. If the condition has been corrected, system is okay. If the condition has not been corrected, go to step  3.
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