I have a onboard charger that has I believe 3 banks. One says main, the other 2 say Aux 1 and Aux 2. The other end of the charger has 4 post. One
set of posts says 12 volt and the other set says 24 volt. All four post read output. First how do I test the charger to see what it is putting out if anything at all and which end do I hook the batteries to??