For 1990-2009 cars

### Using Test Antenna

Note: Use a test mast antenna to quickly check for poor vehicle antenna operation. Unplug antenna lead-in connector from radio receiver and plug a test antenna into radio. Make sure the test antenna base is grounded to the vehicle chassis and keep hands off the mast. Check radio reception in an area away from electrical interferences. Tune to several weak and strong AM and FM stations. If the radio reception improved, the problem exists with the vehicle antenna and/or lead-in cable. If the reception is still poor, refer to Audio System Trouble shooting Hints.

### Antenna Ground Test

Warning: Refer to Battery Disconnect Warning in the Preface section.

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

1. Disconnect the negative battery cable.
2. Disconnect the antenna lead-in connector from the radio receiver.
3. Measure the resistance from the negative battery cable to the coaxial cable, outer conductor, connector.
4. The resistance measured should be 0.2 ohm or less.
5. Test the following when the resistance is greater than 0.2 ohm.

• | Base of the antenna for a poor connection to body ground

• | The coaxial cable interconnects for a poor connection or corrosion.

• | Test for an open or high resistance from the battery negative cable to the body.