For 1990-2009 cars

## Radio Poor Reception Rear Glass

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Radio/Audio System Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check - Radio/Audio System
2 |

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?

--

Go to Audio System Troubleshooting Hints

Go to Step 3

3 |

1. Inspect the antenna coaxial cable for proper connections at the antenna amplifier module.
2. Inspect both harness connectors at the antenna amplifier module for proper connections. 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 18

Go to Step 4

4 | Does poor or no reception occur only on AM? | -- | Go to Step 5 | Go to Step 6
5 |

1. Turn OFF the ignition.
2. Disconnect the antenna amplifier module harness connector C1.
3. Turn ON the ignition, with the engine OFF.
4. Turn ON the radio.
5. Measure the voltage from connector C1 terminal 2 to a good ground.

Does the voltage measure near the specified value?

12 V

Go to Step 6

Go to Step 9

6 |

1. Turn OFF the ignition.
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection
3. Remove the radio. Refer to Radio Replacement for service procedure.

Important: Always zero out the DMM before taking a resistance measurement 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 10

Go to Step 7

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

1. Remove the antenna coaxial cable from the radio and antenna amplifier module.
2. Measure the resistance of the antenna cable center conductor between the radio and the antenna amplifier module.

Does the resistance measure greater than the specified values?

RG-58/RG-59 Coax: 0.20 ohms

RG-62/RG-62M Coax: 3.5 ohms

Go to Step 11

Go to Step 8

8 |

1. Test for continuity between the antenna coaxial cable center conductor and metal case.
2. Test at the opposite end of the antenna cable also.

Did you measure continuity?

--

Go to Step 15

Go to Step 12

9 | Test the antenna relay coil voltage circuit for an open, short to ground or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 13
10 | Test the antenna amplifier module case ground for an open or high resistance. Refer to Circuit Testing in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 14
11 | Inspect the antenna coaxial cable interconnects for a poor connection or corrosion. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 15
12 | Inspect for poor connections at the antenna amplifier module. 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 18 | Go to Step 16
13 | Inspect for poor connections at 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 18 | Go to Step 17
14 | Test for an open or high resistance from the negative battery cable to body ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 18 | Go to Step 11
15 | Replace the antenna coaxial cable. Did you complete the replacement? | -- | Go to Step 18 | --
16 | Replace the antenna amplifier module. Did you complete the replacement? | -- | Go to Step 18 | --
17 | Important:: Perform the setup procedure after replacing the radio. Refer to Radio Setup Replace the radio. Refer to Radio Replacement Did you complete the replacement? | -- | Go to Step 18 | --
18 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2

## Radio Poor Reception Fixed Mast

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Radio/Audio System Schematics
1 | Did you perform the Radio/Audio System Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check - Radio/Audio System
2 |

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 tune to a known strong FM station.

Is the radio reception clear?

--

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

Go to Step 3

3 | Inspect for the following:

• | Radio antenna coaxial cable interconnects for corrosion and proper connection

• | Proper connection at the antenna

Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 4

4 |

1. Turn OFF the ignition.
2. Disconnect the negative battery cable.
3. Disconnect the coaxial cable at the antenna.
4. Zero the digital multimeter (DMM).
5. Measure the resistance between the negative battery cable and the coaxial ground at the antenna.

Is the resistance within the specified value?

0 - 0.6 ohms

Go to Step 5

Go to Step 6

5 |

1. Connect a DMM between the negative battery cable and the coaxial ground at the antenna.
2. Grasp the antenna mast.
3. Monitor the DMM and wiggle the antenna mast.

Does the DMM display intermittent continuity?

--

Go to Step 7

Go to Step 8

6 | Inspect the radio for a proper connection to ground. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11
7 | Inspect the antenna base for a proper connection to the body ground. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 9
8 |

1. Remove the antenna coaxial lead-in connector from the radio.
2. Measure the resistance between the antenna coaxial lead-in (center conductor) connector and the antenna mast. Refer to Circuit Testing in Wiring Systems.

Is the measured resistance less than the specified values?

RG-58/ RG-59 Coax: 0.2 ohms

RG-62/ RG-62M Coax: 3.5 ohms

Go to Step 10

Go to Step 11

9 | Inspect the ground connection from the battery negative cable to the body. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11
10 | Test for continuity between the antenna coaxial cable center conductor and metal case on both ends of the cable. Did you measure continuity? | -- | Go to Step 12 | Go to Step 11
11 | Inspect the radio antenna coaxial cable interconnects for a poor connection or corrosion. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12
12 | Repair or replace the radio antenna coaxial cable circuit. Did you complete the repair or replacement? | -- | Go to Step 13 | --
13 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Audio System Troubleshooting Hints