The battery in my T is hooked up with negative ground. The ammeter shows charging. Any real problem?
That's correct for a T. It's the Model A's and newer Fords that's the other way around.
What gave you the impression that a negative ground battery hookup was backwards. That is the way Ford originally designed it and the way that most Model T owners ascribe to. Jim Patrick
Gordon, your post makes me wonder if maybe you also own a car or more that have the positive ground, such as a Model A as Roger mentioned. I have an "A" also along with my 4 T's...as a suggestion I have found it is very helpful to mark on the positive ground cars that distinction somewhere near the battery so as not to be confused when it's time to hook up either a battery charger, or jumper cables. When you're so used to the typical negative ground, it's very easy to forget yourself when you step up to a positive ground battery for hook-up. Learned the hard way. I mark all my various batt's., per the type of ground, AND voltage..oh yeah, I have both 6V and 12V.
Now the T won't mind much should you choose to connect the battery positive ground, just give the generator a jolt of the new polarity and switch the ammeter cables, then you're OK if you have the original style cutout. With a modern Fun project voltage regulator or a diode cutout you must change to an opposite polarity version.
It's also possible to install a 12 v battery - you'll just have to change the bulbs and adjust the third brush on the generator to get an output the generator can withstand = half the amperes as on 6 volts. There are disadvantages like risk for breaking the Bendix spring much more often, (can be fixed by rewiring of the starter) so actually I'm not advocating making the electrical system any more non standard than just putting a Fun Projects regulator in place of the cutout to save the battery and the generator some unnecessary wear.
It should be noted that the posts on the battery are different diameters ... I forget which is larger.
The point is, if you find one of the terminals falling onto the post and the other waaay too tight, you've got the battery in the other way around.
Tim, your are correct,I also have a 30 Model A Phaeton which of course is positive ground.
Thanks guys for the quick responses. Gordon