I went back and checked the voltage of the charger side connections, be damn careful if you try this, don't touch two pins at the same time! Checked for DC volts, I'm seeing nearly 5V on the front to back, front positive. About 0.7 middle to back, the remaining 4.25 or so front to middle. Positive was always towards the front.

Oh, and in case you are not familiar, the resistance I mentioned earlier might be the funny looking upside down U on the meter, if it doesn't say ohms. If I'm stating the obvious, my apologies, just trying to help.

Cheers