GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the radio/audio system diagnostic system check?

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Go to Step 2

Go to Diagnostic System Check - Radio/Audio System

2

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Disconnect the negative battery cable.
  2. Disconnect the fixed mast antenna lead-in connector at the radio.
  3. Measure the resistance between the coaxial (outer conductor) of the fixed mast antenna lead-in connector and the negative battery cable.

Notice: Remember to "zero" the meter before taking measurements. When checking resistance, cautiously wiggle the lead-in tip and cable. The readings below should always be obtained. If not, some portions of the lead-in is intermittent and the lead-in should be replaced.

Is the resistance within the specified range?

0-0.15 ohms

Go to Step  3

Go to Step  4

3

  1. Grasp the fixed mast antenna.
  2. Measure the resistance between the coaxial (outer conductor) of the fixed mast antenna lead-in connector and the negative battery cable.
  3. Wiggle the fixed mast antenna.

Does the resistance reading display intermittent continuity?

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Go to Step  4

Go to Step  5

4

  1. Inspect the base of the fixed mast antenna for a good connection to body ground.
  2. Inspect the coaxial cable interconnects for a poor connection or corrosion.
  3. Inspect the ground connection from the negative battery cable to body ground. Repair or replace the fixed mast antenna as necessary. Refer to Radio Antenna Replacement .

Did you complete the repair?

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Go to Diagnostic System Check - Radio/Audio System

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5

Measure the resistance between the radio coaxial lead-in connector (center conductor) and the fixed mast antenna.

Is the resistance within specified range?

0-3.5 ohms

Go to Step  6

Go to Step  7

6

  1. Grasp the fixed mast antenna.
  2. Measure the resistance between the radio coaxial lead-in connector (center conductor) and the fixed mast antenna.
  3. Wiggle the fixed mast antenna.

Does the resistance reading display intermittent continuity?

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Go to Step  7

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7

  1. Inspect the coaxial cable interconnects for a faulty connection.
  2. Inspect the coaxial cable interconnects for corrosion.
  3. Repair or replace the interconnects as necessary. Refer to Connector Repairs in Wiring Systems.

Did you complete the repair?

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Go to Diagnostic System Check - Radio/Audio System

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