Testing For Good Ground of Antenna Mounting and Connections
Poor grounding at the antenna mounting or any connection in the antenna/lead-in system can result in seriously reduced radio performance. A poor ground can be a reason for excess ignition noise on AM or erratic audio. Also, be sure lead-in connectors are free of dirt and corrosion and are tightly fastened.Possible ground loss or high-resistance ground points are:
^ Antenna upper mounting (loose screws, paint overspray, etc.).
^ Lead-in cable connector at antenna (loose or internally corroded).
^ Lead-in cable connector at radio (loose or internally corroded).
^ Quick connect connector (corroded).
^ Missing or loose ground strap.