Yes, the balun is inside the housing for that antenna. At this point, you must consider that any part of the system is suspect and it will be necessary to substitute each, one-by-one, with a known good part, even if it means that you end up with a completely separate system. That seems like a lot of work, but it is easier than guessing.
The CB-8269 Cartridge Housing has been known to have problems; I consider it the weakest link in an otherwise good design. There is a troubleshooting video by Winegard:
How To Troubleshoot a Winegard Antenna Cartridge Housing
https://www.youtube.com/watch?v=TlQk...ule1MX8jCAfvPQ
http://www.solidsignal.com/pview.asp?p=cb-8269
http://www.winegarddirect.com/viewit...(CB8269)&post=
interesting mod
https://www.youtube.com/watch?v=mpZNtxy4INM
He soldered the external balun wires to the prongs, but that doesn't improve the connection between the prongs and the wires from that part of the antenna.