Car aerials operate using coaxial cable to connect the aerial to the radio, so repairing or splicing is similar to any other project using coaxial cable. Splicing one cable to another allows you to join two separate cables together into one connection. The cable consists of an outer rubber insulation, a wire mesh, a plastic insulator, and the central conductor wire. Using a barrel plug to splice the two ends of the cables together will ensure a solid connection.
Turn off the car and remove the key from the ignition. Pop the bonnet on the car and remove the positive (red) battery cable from the battery terminal. This will ensure there is no electrical current following through any of the wiring in the car.
Locate the two ends of the car aerial to be spliced together. Depending on where the existing cable is broken or frayed, you may need to remove the car's control console unit, take up carpeting or remove interior trim to access the cable. Cut a 6.5 mm (1/4 inch) off each end of the cables to ensure the end of the cables are clean with a fresh cut.
Insert the end of one of the cables into the larger hole on one end of a cable stripper tool. Strip off 2.5 cm (1 inch) of the outer insulation. Flip the tool over to the other end and insert the same cable into the smaller hole and strip off a 1.25 cm (1/2 inch) of wire mesh and plastic insulator, to expose the central conductor. Repeat this step to strip the end of the other coaxial cable.
Slide the stripped end of one of the cables into the end of one of the male connectors. Place the crimping tool over the bottom of the male connector and squeeze the handles of the tool together so the jaws of the tool clamp down on the connector and press the connector to the cable. Repeat this step to attach the remaining male connector to the other cable.
Screw one of the male connectors into one end of the barrel connector. Screw the other male connector into the other end of the barrel connector to complete the splice. Use the wrench to tighten the connectors to the barrel plug. The barrel connector is a small fitting that has two female threaded holes on each side. It will allow you to join to the two male connectors on each end of the cable together.
Wrap electrical tape over the connectors, starting on one cable and finishing the wrap on the other cable.
Reconnect the battery cable to the battery and tighten it down. Insert the key into the ignition and turn it to accessory mode. Turn the radio on and test the connection by tuning in various stations.
Buy a coaxial cable connector splicing kit to complete the project. The kit will contain all the tools and connectors needed for this project. Or you can buy each of the tools and connectors separately. Each should be available at a local hardware or electronics shop/
Avoid touching the positive (red) and negative (black) battery cables together or allowing the wrench to touch the two battery posts simultaneously, as this could result in electrical sparks or a fire.