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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1848 (HVAC System - Manual) >> Diagnostic Information and Procedures >> Blower Motor Malfunction >> Test Description

Test Description

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

  1. 3:  Test the Low, Med 1, Med 2 and High blower motor control circuits for an open, short to voltage, short to ground or high resistance. The High speed blower motor control circuit is spliced to the Blower motor resistor circuit. This circuit should be checked also.
  2. 7:  Check the connection by removing and securely reinstalling before replacement of the HVAC control is considered.
Blower Motor Malfunction

Step Action Yes No
Schematic Reference: HVAC Schematics 
Connector End View Reference: HVAC Connector End Views 
DEFINITION: The blower motor operates in at least one, but not all, speed positions.
1 Did you perform the Diagnostic System Check - Vehicle? Go to Step 2  Go to Diagnostic System Check - Vehicle
2
  1. Turn ON the ignition, with the engine OFF.
  2. Place the blower motor switch in each speed position.
Does the blower motor operate at the desired speeds?		 Go to Testing for Intermittent Conditions and Poor Connections Go to Step 3 
3 
  1. Turn OFF the ignition.
  2. Disconnect the blower motor resistor assembly.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the LOW, MED 1, MED 2 and HIGH blower motor control circuits at the blower motor resistor assembly and HVAC control assembly, with a test lamp that is connected to voltage. At the same time, place the blower motor switch in the appropriate speed position for the circuit being tested.
Does the test lamp illuminate on all blower motor control circuits?		 Go to Step 5  Go to Step 4 
4 Test the applicable blower motor control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 10  Go to Step 7 
5 Test each blower motor control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 10  Go to Step 6 
6 Inspect for poor connections at the harness connector of the blower motor resistor assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 Go to Step 10  Go to Step 8 
7  Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 Go to Step 10  Go to Step 9 
8 Replace the blower motor resistor. Refer to Blower Motor Resistor Replacement .
Did you complete the replacement?		 Go to Step 10  -
9 Replace the HVAC control module. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 Go to Step 10  -
10 Operate the system in order to verify the repair.
Did you correct the condition?		 System OK Go to Step 2 
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