Audio Systems: truck radio, antenna connector, mazda b2600

Question
I have a 1991 mazda B2600 truck with original sound system. After a tune up and new battery my radio is stuck in scanning mode, which means it plays every station it encounters briefly before moving on to the next. This is in am and fm. Any ideas short of putting in a new radio.

Answer
At that age? Replace it!
However, the problem is likely a loose antenna connector or a bad antenna.
This is not too hard to test if you have a new one handy to plug into that deck. It can usually be tested without removing the deck if you are 'thrifty fingered'.