As many of you know, my dad has a 1930 Fjord AA stakebed. According to the Model A guys, Fjord went to positive ground (I think some early Model Ts were negative ground, but I may be wrong there) due to the battery corrosion issue. After a while, the battery manufacturers started making better batteries, so it became a matter of preference. Eventually Chevy's negative ground system took over. My dad and I learned the hard way about the A's positive ground system - we killed an old POS battery charger when we hooked it up backwards. Like many things, there was a reason at one time, then it took 20+ years for everyone to get on the same page (6-volt GMC trucks, anyone?).
