I'm not real familiar with how the Cyclones are setup, but it sounds like it may be similar to my Fuzion. We were in the same boat and my quick fix was to get a headphone jack to RCA adapter. Keystone had run a 3 wire A/V cable from the stereo/DVD player to the TV just to get the video signal there but they weren't using the sound wires. I plugged them into the AUX input on the back of the stereo and plugged the other end into the TV via my headphone adapter. Now the sound from the TV plays through the stereo just fine.
Worst case, if they didn't run the extra wires already, you could probably tape a 3 way wire to the existing video wire and pull it back through to make it work.