RV Repair: TV, deep cycle battery, volt tv

Question
I have a 1995 Jayco conversion motorhome. I have two problems. One: when I run the engine the tv works fine. When I rely on my house battery the available viewing area on the tv screen gets smaller and unstable. When I hook up shore power the tv acts the same as when I have the motor off thus a small screen and unstable picture. It seems the the twelve volt tv can't get enough power except when engine is running. Any ideas?
Two: I have a Thetford electric porta potty ( Bench style) C-2 model. I've filled the tank with water and all I get is a clicking sound from a metal cylinder mounted just under the seat when I attempt to evacuate the bowl.I can't find a pump and it doesn't seem to run off the house water pump (the sink). I would greatly appreciate any thoughts on either of these subjects.
 Thanks You.....Sean

Answer
Question number one - it's sounds to me like the coach battery is not holding full charge (less than 12 volts)  and should be tested and probably replaced with a deep cycle battery. You also might have a converter/inverter problem.  Have whatever you have looked at by an RV tech.
Question number two - I don't have any experience with this model and thus can't help you much.  Most rv manufacturers have support functions on their websites, you might want to try that.