a friend has been running 2 cannon 5 mag down riggers off his main deep cell starting motor,whitch is hooked to all the electronics in the boat. being worried over if running downrigers all day would leave him stranded, he bought a seperate marine battery deep cell, the downriggers have 3 position switches, up down&auto meaning if you hold the toggle up for about a second it will raise to a predeterminded stop. both units work perfect while hooked to the main battery, but when hooked to the other battery only the up & down work, not the auto, iwill add the second battery is just setting in the back of the boat on the floor. does anyone know what might be going wrong here? thanks for any help