Recreational Vehicle Lpg Tank Valve/gauge problems of the 2007 Ford Five Hundred

This is not the first time I have complained nor am I the only one having this issue. I bought the car back in 2010 and informed the car lot of flickering lights well now its gone as far as my whole dash lights flicker and when they come back they do not come back correctly all the time. My gas gauge doesn't register properly. This happens when I run the ac. When I had it checked I was told that it had something do with battery. The alternator is pulling too much power when ac is on. Well if I am not the only one having this issue I don't understand why this is not getting a better settling besides OH I think it is this or I think it is that. I have searched youtube and there are a lot of ppl having this issue. A whole lot of ppl. I am going to go have my battery checked again and take back to car lot again and hope to have a solution. This is getting really ridiculous and bad. I can run my ac for may 10 minutes without this happening and once I do the car doesn't wanna run properly after. Please look into this and reach out to other owners and see if they are having same issues. Maybe they don't know how ot reach you like I did.