GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

1

Inspect fuses EF20 and EF21.

Is any fuse open?

--

Go to Step 2

Go to Step 3

2

  1. Inspect for a short circuit and repair it, if necessary.
  2. Replace the fuse.

Is the repair complete?

--

System OK

--

3

  1. Turn the ignition ON.
  2. Measure the voltage at fuse EF20 and EF21.

Does the battery voltage available at these fuses measure within the specified range?

11-14 V

Go to Step 4

Go to Step 7

4

  1. Turn the hazard lamp switch ON.
  2. Remove each of the inoperative lamps from its socket.
  3. Test each lamp socket positive terminal with a voltmeter.

Does the battery voltage pulsing at the turn signal, hazard lamp socket positive terminal measure within the specified range?

11-14 V

Go to Step 5

Go to Step 9

5

At each bulb socket, use an ohmmeter to measure the ground circuit.

Is the resistance equal to the specified value?

0 Ω

Go to Step 6

Go to Step 8

6

Replace any faulty turn signal/hazard bulbs.

Is the repair complete?

--

System OK

--

7

Repair the power supply circuit to fuses.

Is the repair complete?

--

System OK

--

8

Repair the open ground circuit.

Is the repair complete?

--

System OK

--

9

  1. Disconnect the hazard switch connector.
  2. Turn the ignition ON.
  3. Measure for voltage at terminal 8.

Does the battery voltage available at terminal 8 measure within the specified range?

11-14 V

Go to Step 10

Go to Step 12

10

  1. Remove the hazard switch.
  2. Turn the hazard switch to the OFF position.
  3. Inspect for continuity between terminals 7 and 8.
  4. Turn the hazard switch ON.
  5. Inspect for continuity between terminals 7 and 8.

Do both tests show the specified value?

0 Ω

System OK

Go to Step 11

11

Replace the faulty hazard switch.

Is the repair complete?

--

System OK

--

12

Repair the open circuit between the hazard switch and the fuses EF20 and EF21.

Is the repair complete?

--

System OK

--