I disconnected my trailer batteries so i could place them on...

I disconnected my trailer batteries so i could place them on a trickle charger. When I hooked them back up I get no lights when on the battery power. When connected to house power all lights work. I replaced the batteries and tried again. No luck. The 30 amp fuse in line from the battery is fine. All fuses in control panel are fine. I can't help but think I hooked something up wrong on the battery. There are two wires coming from the trailer as well as the break disconnect and the ground. How should it all hook up?