GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

If applicable, connect a scan tool and command the condenser fan ON. If the relay energizes, the malfunction is in the fan motor, the wiring between the relay and G105 or burned relay contacts. If the relay does not energize, the malfunction is in the relay, the PCM, or the relay control wiring.

1

Did you review the HVAC Compressor/Condenser Fan Circuit Description and perform the necessary inspections?

Go to Step 2

Go to Diagnostic Starting Point - HVAC Systems - Manual

2

  1. Start the engine.
  2. Turn the blower switch to any position except the OFF position.
  3. Turn the A/C switch to the ON position.

Does the condenser fan motor operate?

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

Go to Step 3

3

  1. Disconnect the A/C condenser fan connector.
  2. Connect a test lamp across the condenser fan connector.
  3. Start the engine.
  4. Press the A/C switch to ON.
  5. Turn the blower speed selector switch to any position except OFF.

Does the test lamp illuminate?

Go to Step 4

Go to Step 5

4

Replace the A/C condenser fan. Refer to Condenser Fan Replacement .

Is the repair complete?

Go to Step 18

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5

Connect a test lamp from cavity 1 of the A/C condenser fan connector to ground.

Does the test lamp illuminate?

Go to Step 6

Go to Step 7

6

Repair the open in the BLK ground wire between the A/C condenser fan motor and G105. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 18

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7

Backprobe the A/C condenser fan relay connector with a test lamp from cavity 4 to ground.

Does the test lamp illuminate?

Go to Step 8

Go to Step 9

8

Repair the open in the RED/BLU wire between the A/C condenser fan relay and the A/C condenser fan. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 18

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9

Backprobe the A/C condenser fan relay connector with a test lamp from cavity 2 to ground.

Does the test lamp illuminate?

Go to Step 11

Go to Step 10

10

Repair the open in the RED/BLK wire between the A/C condenser fan relay and the A/C fuse, or between the A/C fuse and S209. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 18

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11

Backprobe the A/C condenser fan relay connector with a test lamp from cavity 1 to ground.

Does the test lamp illuminate?

Go to Step 13

Go to Step 12

12

Repair the open in the YEL/GRN wire between the A/C condenser fan relay and the DEF fuse. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 18

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13

  1. Disconnect the A/C condenser fan relay connector.
  2. Connect a test lamp from connector cavity 3 to B+.

Does the test lamp illuminate?

Go to Step 14

Go to Step 15

14

Replace the A/C condenser fan relay. Refer to Condenser Fan Relay Replacement .

Is the repair complete?

Go to Step 18

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15

Test for an open in the YEL/BLU wire between the powertrain control module (PCM) connector 1 cavity 22 and the A/C condenser fan relay.

Is an open present?

Go to Step 16

Go to Step 17

16

Repair the open in the YEL/BLU wire between the PCM and the A/C condenser fan relay.

Is the repair complete?

Go to Step 18

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17

Verify that the A/C compressor clutch engages. If the clutch does not engage, refer to HVAC Compressor Clutch Does Not Engage . If the clutch engages, replace the PCM. Refer to PCM Replacement in Engine Controls.

Is the repair complete?

Go to Step 18

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18

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3