Instructions
Plug one end of the RCA cables that come with your Wii into the AV Multi Out connector slot on the back of the game console. There will be a combination of red, white and yellow plugs, joined together in one wire. Plug the AC power cord into the back of the Wii.
Plug the other ends of the RCA cable into the input jacks on the back of your Comcast cable box. They should be labeled "Video In" and "Audio In." The yellow cable will be inserted into the video jack, the white cable into the "Audio L" and the red cable into "Audio R." Plug the AC cord into an electrical outlet close to the television and the game console.
Turn on the power for the Comcast cable box, the television and the Wii console. Press the "Input/TV/VCR" button on the Comcast box remote to change the input settings of the box. The Wii's menu should appear if all the connections are tight. You can now control the game console and your cable connection with one remote, without unplugging any devices.