[WeBeFulltime]

On your 08 3400 the valve should be located in the wall between your shower and the kitchen pantry. Open pantry and look on wall for access covers made of plastic. My 08 3400 had this and the valve was located behind the cover. Should be an easy fix. Much easier to just delete the valve and install one of the screw-on faucet type at the black tank hook-up in the convenience center. Cost should be less than $10 if you do it yourself.