GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

DEFINITION: Hazard lamps are inoperative. Turn signal lamps may also be inoperative.

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 hazard lamp switch to the ON position.

Do all of the turn signal tamps flash ON and OFF?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Disconnect the hazard switch.
  2. Probe the hazard switch voltage supply circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 9

4

With the hazard switch in the ON position test for less than 1 ohms of resistance between the hazard switch voltage supply circuit and the hazard switch signal circuit.

Is the resistance within specification?

Go to Step 5

Go to Step 14

5

With the hazard switch in the ON position test for less than 1 ohms of resistance between the turn signal flasher relay and both of the hazard lamp voltage supply circuits.

Is the resistance within specification on both of the hazard lamp voltage supply circuits?

Go to Step 6

Go to Step 14

6

  1. Connect the hazard switch.
  2. Disconnect the turn signal flasher relay.
  3. With the hazard switch in the ON position connect a test lamp between the hazard switch signal circuit and a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 10

7

With the hazard switch in the ON position connect a test lamp between the hazard switch signal circuit and the turn signal flasher relay ground circuit.

Does the test lamp illuminate?

Go to Step 8

Go to Step 11

8

With the hazard switch in the ON position connect a test lamp between the hazard switch signal circuit and the turn signal flasher relay signal circuit.

Does the test lamp illuminate?

Go to Step 15

Go to Step 13

9

Repair the poor connections at the harness connector or the hazard switch.

Did you complete the repair?

Go to Step 16

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10

Inspect for a poor connection at the harness connector of the hazard switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 16

Go to Step 12

11

Repair an open, or high resistance in the turn signal flasher relay ground circuit. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 16

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12

Repair the following in the hazard switch signal circuit:

    • An open
    • A high resistance
    • A short to ground

Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 16

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13

Repair an open, high resistance on the turn signal flasher relay signal circuit. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 16

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14

Replace the hazard switch.

Did you complete the replacement?

Go to Step 16

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15

Replace the turn signal flasher relay.

Did you complete the replacement?

Go to Step 16

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16

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3