so ive got a single mariner outboard with 2 batteries in board. i put my perko switch on the 1 setting, it works great, setting 2 and its like i have a dead battery. heres the catch, i have switched the batteries and the same thing happens. both batteries have 12.4 volts, both work fine when i hook them up to the front set of wires(#1). i replaced the hot wire to the back battery (#2) from the switch and replaced the ground wire to the engine (back battery). can that perco switch go bad? and if it is not likley is there any thing else i can look at? thanks for the help.
