I was asked to help a friend who has a 39 ford N and not much knowledge of its history. In short I need guidance testing the starting system as it won't turn over. Here's what I know. It is positive ground on 8 volt battery. I am unsure of what battery should be in it, 6 or 12. It has an alternator as opposed to generator. I am going over to get serial number for more info later but would like some guidance on testing the no crank issue. I have volt meter and battery shows 8.5. How should I further test it and does anyone have a theory? Of course it had run fine and then one day nothing. Thanks Greg.