Always perform the Diagnostic System Check before proceeding with these diagnostic procedures. Refer to Diagnostic System Check - Vehicle in Vehicle DTC Information.

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 Troubleshooting Hints .

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

1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
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 0.20 ohms or less.
5. Test the following when the resistance is greater than 0.20 ohms.

•	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. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

6. After finding and correcting the condition, operate the system in order to verify the repair.

Use the appropriate chart and diagram to test the antenna coaxial cable resistances for the antenna system on the vehicle. Refer to the table when testing the antenna and/or lead-in cable.