I have a Sunlite popup truck camper and when I fist got it the battery would charge with my generator running or plugged in to shore power . For some reason when I changed batteries I thought there were three wires going to the battery but now I only have two . It has since quit charging . All the fuses are in good order and I don't see any broken connections . I am getting older and forgetful so if someone could clear this question of wires for me I will be eternally grateful .