where did the "tv out" setting go on my iPhone 3gs with iOS 6.0?

I used to be able to use my rca cable video and audio cable out to send video and things like you tube to my tv, but I tried again recently and it does not work. The "TV out" on and off setting in settings is gone now and I can not find a way to get the Iphone 3gs to recognize the video cable or send video out. I am using the newest iOS. I think it is 6.0.1 Is the setting gone and no longer possible to send the video or is there a trick that I dont know. Does anyone know of an app that will allow this? I want to send the video and audio on the phone to the tv monitor in my truck for my kids to watch. It used to work fine but now it doesnt. The only thing different is the iOS is different on the phone.