I think in some cases, the antenna action is triggered by the radio being switched on - it has some electronic trickery inside, that sends juice to the antenna relay. Perhaps then your antenna switch is an after-market addition?
I'm thinking of putting one in my car, since my stereo's antenna feed doesn't work, and I can't be bothered to get it fixed at great expense! All you need is a 12V source in place of what the radio would normally provide, and a switch to control it...

on some radios the antenna was raised and lowered by the power to the radio. when you turned the car on or the radio on, the power antenna would raise it. when you shut the engine off or the radio off, it would lower. as you can guess this would raise and lower it quite a lot causing the motor to wear out early. also some times the radio would not get the signal that the antenna was up and it would keep the motor running until it burned up. i have had quite a few friends that added their own switch to over ride the automatic control

On my 77 the switch controls the rear window defroster. Green light glows when on!!!!

Same on my '77,but my defroster doesnt work...any suggestions?It looks like the grid may be the problem.I know the switch is defroster because you can just make out a few letters,& I dont have a power antenna.

If, when you flick the switch, the relay gives out a "click", then you know you're getting things working up to that point - if not its probably a case of checking fuse, connections etc (great fun!) The grid should still work on any of the lines which aren't broken - quite a few of mine are discontinuous, but I've heard of people using conducting aluminium spray paint to fill any breaks - not tried that myself yet....
Don't know where your relay would be - are they inthe jack box, like mine, on the earlier cars?