When you turn it on, does it hummm? If not the vibrator is stuck. It is the big metal can inside the radio. Pull it straigt out, and strike it on you hand with several sharp blows. This should open up the vibrator points. Put back in radio, making sure to line up the prongs on the vibrator with the holes in the radio chasis.
If this doesn't work the antenna may be disconnected from the radio, and the trimmer needs adjustment.
Removing such a radio would give one a chance to check its overall condition, and blow away any dust accumulation. To remove its two nuts behind the volumne and station selector, and under the dash two bolts, the power line and the antennae. I Guess, if you are able, a crawl under the dash is on the agenda.