".the red and white on back of my Westinghouse TV , says av-input..for the red and white plug."
I am just checking but you did say input. If you are trying to plug a sound bar into the tv a/v input you wont get anything. you need to look for a set of RCA audio out put which will still be red or white.
without you stating the tv model I am not sure if you even have any. I just purchased an RCA today and it was without so i tripped across this thread. The DCA suggest will solve my problem as I have a Digital Audio out which is both the red and white audio channels combined so now i can split them into an old dvd surround sound that i have.