GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2007 🢒 Canyon Pickup - 2WD 🢒 HVAC 🢒 HVAC - Manual 🢒 Blower Motor Always On

Test Description

The number below refers to the step number on the diagnostic table.

  1. The blower motor should not operate with the ignition in the OFF position.

Step

Action

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: The blower motor is ON while the blower motor switch is in the OFF position or blower motor is ON when the ignition is OFF.

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 the OFF position.

Is the blower motor OFF?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Place the blower motor switch in each speed position.

Does the blower motor operate with the ignition in the OFF position?

Go to Step 4

Go to Step 5

4

Disconnect the IGN 3 relay.

Does the blower motor turn OFF?

Go to Step 11

Go to Step 9

5
  1. Turn OFF the ignition.
  2. Disconnect the blower motor resistor assembly.
  3. Turn ON the ignition, with the engine OFF.

Is the blower motor OFF?

Go to Step 6

Go to Step 7

6

Test the Low, Med 1, and the Med 2 blower motor control circuits for 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 10

7

Disconnect the HVAC control assembly.

Is the blower motor OFF?

Go to Step 10

Go to Step 8

8

Repair the short to ground in the blower motor high control circuit. Refer to Wiring Repairs .

Did you complete the repair?

Go to Step 13

--

9

Repair the short to voltage in the blower motor supply voltage circuit. Refer to Wiring Repairs .

Did you complete the repair?

Go to Step 13

--

10

Inspect for poor connections at the harness connector of the HVAC control assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 13

Go to Step 12

11

Replace the ignition 3 relay.

Did you complete the replacement?

Go to Step 13

--

12

Replace the HVAC control assembly. Refer to Heater and Air Conditioning Control Replacement .

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