GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the Radio/Audio System Check performed?

--

Go to Step 2

Go to Radio/Audio System Check

2

  1. Disconnect the C1 connector at the radio.
  2. Connect a digital multimeter J 39200 set on the voltage scale between the C1 connector, cavity 2 for CKT 201 (TAN), and ground.
  3. Place the ignition switch in the RUN position.

Is voltage present?

--

Go to Step 13

Go to Step 3

3

Connect a J 39200 set on the voltage scale between the C1 connector, cavity 1 for CKT 118 (GRY), and ground.

Is voltage present?

--

Go to Step 14

Go to Step 4

4

  1. Place the ignition switch in the OFF position.
  2. Connect a J 39200 set on the ohms scale between the C1 connector, cavity 2 for CKT 201 (TAN), and ground.

Is continuity present?

--

Go to Step 15

Go to Step 5

5

Connect a J 39200 set on the ohms scale between the C1 connector, cavity 1 for CKT 118 (GRY), and ground.

Is continuity present?

--

Go to Step 16

Go to Step 6

6

Connect a J 39200 set on the ohms scale between the C1 connector, cavity 2 and cavity 1.

Is the resistance within the specified range?

4-15 ohms

Go to Step 17

Go to Step 7

7

  1. Disconnect the left front door radio speaker connector, and (if equipped) the left front door radio tweeter connector.
  2. Inspect the connector(s) for damage, corrosion or loose fit.

Is each connector in good condition?

 

Go to Step 8

Go to Step 18

8

  1. Connect a J 39200 set on the ohms scale between the left front door radio speaker connector, cavity A and the C1 connector, cavity 1 for CKT 118 (GRY).
  2. Repeat step on tweeter connector if equipped.

Is continuity present?

--

Go to Step 9

Go to Step 19

9

  1. Connect a J 39200 set on the ohms scale between the left front door radio speaker connector, cavity B and the C1 connector, cavity 2 for CKT 201 (TAN).
  2. Repeat step on tweeter connector if equipped.

Is continuity present?

--

Go to Step 10

Go to Step 20

10

  1. Connect a J 39200 set on the ohms scale between the left front door radio speaker pins A and B.
  2. Repeat step on tweeter if equipped.

Is the resistance within the specified range?

4-15 ohms

Go to Step 11

Go to Step 21

11

  1. Reconnect all connectors.
  2. Place ignition switch in the RUN position.
  3. Tune the radio to a strong, clear station.

Do the speaker(s) have good sound quality?

--

Go to Radio/Audio System Check

Go to Step 12

12

Substitute a known good speaker for the speaker with poor sound quality.

Does sound quality improve?

--

Go to Step 21

Go to Step 17

13

Repair the short to voltage in CKT 201 (TAN).

Refer to Wiring Repairs .

Is the repair complete?

--

Go to Radio/Audio System Check

--

14

Repair the short to voltage in CKT 118 (GRY).

Refer to Wiring Repairs .

Is the repair complete?

--

Go to Radio/Audio System Check

--

15

Repair the short to ground in CKT 201 (TAN).

Refer to Wiring Repairs .

Is the repair complete?

--

Go to Radio/Audio System Check

--

16

Repair the short to ground in CKT 118 (GRY).

Refer to Wiring Repairs .

Is the repair complete?

--

Go to Radio/Audio System Check

--

17

  1. Remove and replace radio, Refer to Radio Replacement .
  2. Send faulty radio in for repair.

Is repair complete?

--

Go to Radio/Audio System Check

--

18

Repair damaged connector(s).

Refer to Connector Repairs .

Is repair complete?

--

Go to Radio/Audio System Check

--

19

Repair the open in CKT 118 (GRY).

Refer to Wiring Repairs .

Is the repair complete?

--

Go to Radio/Audio System Check

--

20

Repair the open in CKT 201 (TAN).

Refer to Wiring Repairs .

Is the repair complete?

--

Go to Radio/Audio System Check

--

21

Replace the front door speaker or tweeter.

Refer to Radio Front Side Door Speaker Replacement .

Is the repair complete?

--

Go to Radio/Audio System Check

--