Audio Systems: 99 silverado radio, antenna connections, antenna assembly

Question
I have a 99 silverado with a Delco stereo/cd player. It cuts in and out in fm mode while driving like there is a loose connection, but it doesn't do it in fm mode, and it won't do it while at a stop.  Any ideas?

Answer
The antenna connections on 1988 to present GM trucks are notorious for corrosion in the fender area. There is a large rubber cover where the short antenna lead connects to the longer one, before it enteres the cab. My suggestion? Replace the whole antenna assembly, except the mast of course. I do it on every truck we have trouble with, and it is the answer. You may want to seal the outside of the new one to make it last longer.