GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2002 🢒 Sunfire 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Blower Motor Always On

Test Description

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

  1. The mode switch actuates the heater blower relay by applying voltage to the coil side of the relay through the heater blower relay supply voltage circuit. If the test lamp illuminates with the mode switch OFF, the source of the concern is either short to voltage on the heater blower relay supply voltage circuit or a malfunctioning mode switch.

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.

1

Did you perform the HVAC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Manual

2
  1. Turn ON the ignition, with the engine OFF.
  2. Place the mode switch in the OFF position.

Is the blower motor OFF?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3
  1. Turn OFF the ignition.
  2. Disconnect the heater blower relay.
  3. Turn ON the ignition, with the engine OFF.

Is the blower motor OFF?

Go to Step 4

Go to Step 8

4

Important: The mode switch must remain in the OFF position during this step.

Probe the heater blower relay supply voltage circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 6

5

Test the heater blower relay supply voltage circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 7

6

Inspect for poor connections at the harness connector of the blower motor relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 9

7

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 in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 10

8

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

Did you complete the repair?

Go to Step 11

--

9

Replace the heater blower relay. Refer to Blower Motor Relay Replacement in Heating, Ventilation and Air Conditioning.

Did you complete the replacement?

Go to Step 11

--

10

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

Did you complete the replacement?

Go to Step 11

--

11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2