Charging the Battery Question

In scanning text under the battery section of the MODEL A FORD- MECHANICS HANDBOOK I discovered, much to my surprise. that you were supposed to connect the battery cables in reverse of what I had always done on other cars — red to negative etc. I did this after pulling the battery for a charge and then reconnecting – Pretty dumb ! Incidentally, when using a battery charger to charge your battery, do you also hook up the red to the negative post and ground to the plus pole?

Answer:

Remember that the Model A has a positive ground electrical system. Ford was the first automaker to do this and for good reason. Due to gasses from the battery, the positive terminal always has a tendency to collect corrosion and cause poor connection. Ford engineers thought if the applied the positive terminal of the battery to the ground connection (reversing current flow) it would reduce the terminal corrosion and the corrosion that would form would not have as much effect on reduced voltage. …a little bit of trivia. When connecting a battery charger always connect the charger (+) red lead to the Battery (+) side.
— Les Andrews, 1998 Technical Director