GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Schematic Reference: Radio/Audio System Schematics

1

Did you review the Radio/Audio System Description and Operation and perform the necessary inspections?

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Go to Step 2

Go to Radio/Audio System Description and Operation

2

  1. Turn ON the ignition, with the engine OFF.
  2. Turn ON the radio.
  3. Adjust the radio balance and fade controls to each speaker.

Do all of the speakers operate properly?

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

Go to Step 3

3

Are all of the speakers inoperative?

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Go to Step 10

Go to Step 4

4

Is an audio amplifier installed in the Radio/Audio System?

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Go to Step 6

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the radio.
  3. Momentarily touch a 1.5 volt battery between the appropriate speaker output circuits of the radio.

Does the speaker emit an audible pop?

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Go to Step 15

Go to Step 9

6

  1. Disconnect the amplifier.
  2. Adjust the radio volume to 50 percent.
  3. Test the appropriate speaker input circuits of the audio amplifier for AC voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Does the voltage measure greater than the specified value?

0.020 V

Go to Step 7

Go to Step 8

7

Test the appropriate speaker output circuits of the audio amplifier for a short, high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 14

8

Test the appropriate speaker input circuits of the audio amplifier for a short, high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 15

9

Test the appropriate speaker output circuits of the radio for a short or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 17

10

  1. Turn OFF the ignition.
  2. Disconnect the radio.
  3. Test the speaker output circuits of the radio for a short. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 11

11

Is an audio amplifier installed in the Radio/Audio System?

--

Go to Step 12

Go to Step 15

12

  1. Disconnect the amplifier.
  2. Test the battery positive voltage circuit of the amplifier for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 13

13

Test the ground circuit of the audio amplifier for high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 16

14

  1. Disconnect the speaker.
  2. Adjust the radio volume to 50 percent.
  3. Test the appropriate speaker input circuits of the speaker for AC voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Does the voltage measure greater than the specified value?

0.020  V

Go to Step 17

Go to Step 16

15

Inspect for poor connections at the harness connector of the radio. 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 21

Go to Step 18

16

Inspect for poor connections at the harness connector of the audio amplifier. 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 21

Go to Step 19

17

Inspect for poor connections at the harness connector of the appropriate speaker. 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 21

Go to Step 20

18

Replace the radio. Refer to Radio Replacement .

Did you complete the replacement?

--

Go to Step 21

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19

Replace the audio amplifier. Refer to Radio Speaker Amplifier Replacement .

Did you complete the replacement?

--

Go to Step 21

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20

Replace the suspect speaker. Refer to Speaker Replacement Reference

Did you complete the replacement?

--

Go to Step 21

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21

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2