Parallel battery help

[fmoreno68]

I have a crossroads 26RB and had placed the trailer in a storage lot since I can not have it in front of my house. I that if I disconnected the battery ground cable I could save battery and/or protect from someone trying to steel it. Well I went today to pick it up and tried to reconnect it. I'm sure I did it right, but I had no power to the trailer, I couldn't turn the power jack on or lights inside. So I connected it to the truck hoping to help. Well that didn't work either. Then twenty minutes later of figiting with the batteries, i get a error from my truck saying Battery not charging review manual. Does anyone happen to have a picture of what the battery connections should look like? I should have done that before I disconnected it. Oh when I connect the ground I hear a beeping sound form somewhere inside the trailer. i just don't know where it is coming from. Its only for a few short beeps. Please help. We are supposed to leave out of town in three days.