When we drive and our holding tanks are not empty we get an odor that comes from the half bath, with the most prominent odor coming from under the sink. We have tried everything to get rid of the odor. We are under the impression there is a loose connection somewhere over the black tank. Not sure why there is no odor when we are sitting still. 1) Can anyone provide an easy to follow plumbing diagram 2) Has anyone else had/have this issue? We have changed out the stupor valves and have also covered them to try to stem the odor.