the antenna may be able to get unstuck with wd 40 or the like. if it is factory the mast is removable by using, i think its a 12 mm, chrome bolt at the base of the antenna. pull it all out and clean and oil then it should feed back in automatically if you have the radio on then turn it off. two people make this easier. the plastic 'tail' should suck down into the base when you turn the radio off. if the motor doesnt run when the radio is turned on or off then it is an electrical problem. check fuses and the wires. these antennas are very long lived and about 60% of the time the above description will fix the problem.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.