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Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1429 (HVAC Systems - Automatic) >> Diagnostic Information and Procedures >> Air Delivery Improper - Auxiliary (W/O Sunroof) >> Test Description

Test Description

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The number(s) below refer to the step number(s) on the diagnostic table.

  1. 3:  This step tests for auxiliary blower motor that does not operate from the front auxiliary HVAC control assembly regardless of the desired blower motor speed.
  2. 4:  This step tests for a auxiliary blower motor that operates, yet does not accurately respond to the desired blower motor speed from the front auxiliary HVAC control assembly.
  3. 5:  This step tests for an inoperative auxiliary mode actuator in one mode position(s) or in the wrong mode position(s) from the front auxiliary HVAC control module.
  4. 6:  This step tests for an inoperative auxiliary mode actuator in one mode position(s) or in the wrong mode position(s) from the rear auxiliary HVAC control module.
Air Delivery Improper - Auxiliary (W/O Sunroof)

Step Action Yes No
Schematic Reference:  HVAC Schematics  
DEFINITION: Air does not flow correctly from the auxiliary air distribution outlets.
1 Did you review the HVAC operation and perform the necessary inspections? Go to Step 2  Go to Symptoms - HVAC Systems - Automatic 
2
  1. Turn ON the ignition, with the engine OFF.
  2. Place the front auxiliary HVAC control assembly blower control in the OFF position.
  3. Place the rear auxiliary HVAC control assembly blower control in the OFF position.
Is the auxiliary blower motor OFF?
Go to Step 3  Go to Blower Motor Always On 
Place the front auxiliary control assembly blower control in each mode position.
Does the auxiliary blower motor operate at all?
Go to Step 4  Go to Blower Motor Inoperative 
Does the auxiliary blower motor operate correctly for each mode position? Go to Step 5  Go to Blower Motor Malfunction 
  1. Place the front auxiliary HVAC control assembly blower control in the high position.
  2. Place the front auxiliary HVAC control assembly mode control in each mode position.
Does the auxiliary mode actuator operate correctly for each mode position?
Go to Step 6  Go to Step 7 
  1. Place the front auxiliary HVAC control assembly blower control in the rear control position.
  2. Place the rear auxiliary HVAC control assembly blower control in the high position.
  3. Place the rear auxiliary HVAC control assembly mode control in each mode position.
Does the auxiliary mode actuator operate correctly for each mode position?
Go to TESTING FOR INTERMITTENT AND POOR CONNECTIONS Go to Step 10 
7 Test the mode door control - auxiliary circuit of the front auxiliary HVAC control assembly for an open, a high resistance or a short to ground. Refer to CIRCUIT TESTING and WIRING REPAIRS .
Did you find and correct the condition?
Go to Step 13  Go to Step 8 
8
  1. Disconnect the electrical connector from the front HVAC control module.
  2. Test for resistance between the mode door control - auxiliary terminal and the low reference terminal of the front HVAC control module.
  3. Place the front HVAC control module mode control to each mode position.
Does the resistance change between each selected mode position?
Go to Step 10  Go to Step 9 
9 Inspect for poor connections at the harness connector of the front auxiliary HVAC control assembly. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and CONNECTOR REPAIRS .
Did you find and correct the condition?
Go to Step 13  Go to Step 11 
10 Inspect for poor connections at the harness connector of the rear auxiliary HVAC control assembly. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and CONNECTOR REPAIRS .
Did you find and correct the condition?
Go to Step 13  Go to Step 12 
11 Replace the front auxiliary HVAC control assembly. Refer to HVAC Control Assembly Replacement - Front Auxiliary .
Did you complete the replacement?
Go to Step 13  -
12 Replace the HVAC control assembly - auxiliary rear. Refer to HVAC Control Assembly Replacement - Front Auxiliary .
Did you complete the replacement?
Go to Step 13  -
13 Operate the system in order to verify the repair.
Did you correct the condition?
System OK Go to Step 2