Hi A.Post,

You can try those two connectors by connecting at +5V and gnd with a 56 ohm resistor in series. You can check which one is anode or cathode, by exchanging the pins between +5V and ground. A rectrifier diode in series with +5V is recommended in order to avoid any damage to LCDs.
By the way, how much you paid for those LCDs, what is the display size, 16x2 20x2 etc.

Rauf