Thanks again everyone. I think I agree that the more simple the system, the better off I will be, however for now, I have a van with a sensor system.
Question Skyl4rk. I had checked the fuses, all good. I had removed the panel and checked connections, all good. I would like to check if I have power at the switch, and I do have a multi-meter, but I assume I have to be able to pull off the thing that is attached to the panel, in order to check for current. I tugged lightly on them, but they don't come off, and I don't want to do more damage than good. I think I will end up taking this to an RV tech, but as a last ditch attempt, here is a photo of the panel. The black and red wires on the bottom right are to the water pump. It works fine. The yellow and black wires are to the electric start for the water heater. It works fine. The two orange buttons on the bottom left are the ones that I assume are giving me the problem. Since the toggle switch that these two orange buttons are attached to runs both the battery sensor and the tank sensors, I will assume that one is a problem. The battery sensor is working, the tank sensors are not. I would like to test if I have power to these buttons, but I assume I need to remove them to get to the 'live wire' in order to do that, and I don't know how to remove these. Also, I am a novice, and want to do this safely, so if I were to get to the live wire part, what am I supposed to touch to the wire. I read that you touch one end of the multi meter probe to the wire, and the other to a ground? Is this correct and, if so, what would constitute a ground? Sorry, I know I am sounding boarder line dangerous here....but I love to learn....safely, that is. I have read that there are tools that will tell you if the wire is live 'through the insulation' but I don't have one of them. Thanks again.