Schematic Reference: Radio/Audio System Schematics

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

1. Turn ON the ignition, with the engine OFF.
2. Turn ON the radio.
3. Tune the radio to a known strong AM station then to a known strong FM station.

Is the radio reception clear?

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Go to Audio System Troubleshooting Hints

Go to Step 3

1. Inspect the radio on signal circuit connection at the radio antenna amplifier. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
2. Inspect the antenna coaxial cable for the following:

•	Poor connections at the radio antenna amplifier.

•	Poor connection or corrosion at the coaxial cable interconnect. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

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Go to Step 15

Go to Step 4

1. Turn OFF the ignition.
2. Disconnect the smaller radio antenna amplifier connector. Refer to Antenna Amplifier Replacement for service procedure.
3. Turn ON the ignition, with the engine OFF.
4. Turn ON the radio.
5. Measure the voltage from the radio on signal circuit of the radio to a good ground.

Does the voltage measure near the specified value?

12 V

Go to Step 5

Go to Step 6

1. Turn OFF the ignition.
2. Disconnect the negative battery cable.
3. Remove the radio. Refer to Radio Replacement for service procedure.

Important: Always zero out the DMM before taking a resistance measurement in order to ensure an accurate reading.

4. Measure the resistance between the negative battery cable and the radio antenna coaxial ground at the radio.

Does the resistance measure greater than the specified value?

0.20 ohms

Go to Step 7

Go to Step 8

Test the radio on signal circuit for an open, short to ground or high resistance. Refer to Circuit Testing and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 15

Go to Step 9

Test the radio antenna amplifier case ground for an open, or high resistance. Refer to Circuit Testing in Wiring Systems.

Did you find and correct the condition?

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Go to Step 15

Go to Step 10

Important: Always zero out the DMM before taking a resistance measurement in order to ensure an accurate reading.

1. Turn OFF the ignition.
2. Remove the antenna coaxial cable from the radio and radio antenna amplifier.
3. Measure the resistance of the antenna cable center conductor between the radio and the radio antenna amplifier.

Does the resistance measure greater than the specified values?

RG-58/RG-59  Coax: 0.20 ohms

RG-62/RG62M  Coax: 3.5 ohms

Go to Step 10

Go to Step 11

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?

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Go to Step 15

Go to Step 12

Replace the antenna coaxial cable.

Did you complete the replacement?

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Go to Step 15

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1. Test for continuity between the antenna coaxial cable center conductor and metal case. Refer to Circuit Testing in Wiring Systems.
2. Test at the opposite end of the antenna coaxial cable also.

Did you measure continuity?

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Go to Step 10

Go to Step 13

Important:: Perform the set up procedure for the radio.

Replace the radio. Refer to Radio Replacement for service procedure.

Did you complete the replacement?

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Go to Step 15

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Inspect for poor connections at the harness connector of the radio antenna amplifier. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 15

Go to Step 14

Replace the radio antenna amplifier. Refer to Antenna Amplifier Replacement for service procedure.

Did you complete the replacement?

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Go to Step 15

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Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2