Radio initiates antenna operation. Replaced the relay. Problem remains the same: Regardless if radio is powered-on/off... As soon as battery-power is applied to the vehicle... The motor on the antenna runs non-stop... But the antenna remains in the same position. The antenna can be pulled/pushed part-way... But not totally open or closed. Help?
It sounds like the mast drive ribbon, attached to the bottom of the mast, is broken. The mast with ribbon is what would need to be replaced.
The mast is pushed up and pulled down with a heavy plastic cable (for lack of a better term) that goes inside the mast. The cable winds up on a spool driven by the motor. The end of the cable fits into a hole in the spool and this is a stress concentration. It nearly always breaks there. The design of the antenna is such that the motor continues to run until the mast is fully up or down. Limit switches at each end of travel turn the motor off. With the cable broken, the limit switches are never opened, so the motor runs constantly. If this is a GM antenna, you can purchase a replacement mast and rebuild the antenna.
The repair cables are not always the correct ones for the antenna. Some have shorter top segments than others. Use caution when buying the replacement.
When I had my window gaskets replaced the shop that did it didn't know that the antenna was powered. They forced it down and it broke the nylon cord inside. I bought some heavy weed whipper string to fix it. When I got it apart the break was right at the mast and the rest of the 50 year old cord was in excellent shape. I heated the mast with a torch and pulled the broken piece out. I heated the good end pushed it in the mast and gave it a slight crimp. Been working for two years so far.
