GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you review the radio/audio system operation and perform the necessary inspections?

--

Go to Step 2

Go to Symptoms

2

Verify that the antenna reception is poor.

Is the antenna reception OK?

--

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

Go to Step 3

3

  1. Disconnect the negative battery cable.
  2. Disconnect the antenna lead in connector at the radio receiver.
  3. Measure the resistance between the coax (outer conductor) connector and the negative battery cable. Refer to Antenna Diagnostic Check .

Is the resistance less than the specified value?

0.15 ohms

Go to Step 4

Go to Step 7

4

  1. Grasp the antenna mast.
  2. While observing the DMM, wiggle the antenna.

Is continuity intermittent?

--

Go to Step 7

Go to Step 5

5

Measure the resistance between the radio coaxial lead-in connector (center conductor) and the antenna mast. Refer to Antenna Diagnostic Check .

Is the resistance less than the specified value?

3.5 ohms

Go to Step 6

Go to Step 8

6

Observe the DMM, and wiggle the antenna.

Is continuity intermittent?

--

Go to Step 8

Go to Step 9

7

  1. Inspect the base of the 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 battery negative cable to the body.
  4. Repair the antenna ground circuit as needed.

Is the repair complete?

--

Go to Step 10

--

8

  1. Inspect the coaxial cable interconnects for a poor connection or corrosion.
  2. Repair or replace the antenna coaxial circuit as needed.

Is the repair complete?

--

Go to Step 10

--

9

Service the radio. Refer to Radio Replacement .

Is service of the radio complete?

--

Go to Step 10

--

10

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3