I recently bought a LOWRANCE HDS 7 with side scan. I do not have the 3D structure scan module. I mounted the side scan transducer lower than the DI ducer like it instructed. I don't have anything really showing up on the side scan mode. Is this because I don't have the 3D module? I was under the impression that I could still use the SS function it just would not be 3D. Any help with setup on my new unit would be appreciated. Thanks