GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you complete the Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check

2

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the blower motor relay.
  3. Connect a test lamp at the blower motor relay connector terminal A1 and ground.

Does the test lamp illuminate?

--

Go to Step 3

Go to Step 4

3

Repair a short to battery voltage in the control circuit of the high blower motor. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 9

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4

Connect a test lamp at the blower motor relay connector terminal B2 and ground.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 6

5

Repair a short to battery voltage in the blower resistor control circuit of the blower motor.

Did you complete the repair?

--

Go to Step 9

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6

Connect a test lamp at the blower motor relay connector terminal C1 and ground.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 8

7

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

Did you complete the repair?

--

Go to Step 9

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8

Replace the blower motor relay. Refer to Blower Motor Relay Replacement .

Did you complete the replacement?

--

Go to Step 9

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9

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3