To test antenna cables and mast on vehicles made before 1996, disconnect the cable from the radio, put your ohmmeter on it, and measure resistance; readings should be below five ohms. Your antenna is working when the reading shows it's correct. Look at the antenna cable and mast base when reading is wrong. First, measure the resistance between the antenna cable and the radio, then between the cable and the antenna. Resistance under five ohms on each connection is normal; replacing them if they don't measure correctly. Pull the antenna physically from the car to see if the measurement between the base and its center port is under five ohms; this means the antenna is working. Higher readings mean you need to replace it. Disconnect the cable from the negative battery first. Then to remove the front-mounted antenna, lower it down and take away the rear screws behind the right front fender to get to the antenna bolt below. Drop the antenna through the fender opening after removing the top nut from the stanchion and reinstall it by going backwards through this process. To reach the rear antenna, lift the car, then take out the lower antenna bolt after removing the trunk trim panel. Unscrew the antenna cap from the radio, undo the mounting screws, disconnect power connections, lift the antenna down into the trunk of the vehicle, while reversing these steps for correct installation. When the plastic antenna drive cable gets damaged or the mast becomes bent, you must replace both the cable and the mast which stays where it is attached to the motor. Take off the retaining nut. Gently pull the mast out of the motor until the drive cable has room to come off. Record how the drive teeth move as you pull. Detach the old mast with a hacksaw, slip the nut and tube away, insert the new cable into the motor drive, keep running the motor and holding the cable till 12 inches go inside, lower down the new tube and nut, secure the nut firmly, and verify operation by switching on and off the radio antenna a few times.