...just wondering if i should feed +5v into V0 as thats where the wiper went?Typically there is about 1/2 volt on pin 3 when the contrast is set correctly so +5V would not be a good choice.
it says on the back,There should be some sort of photosensitive device on the board to activate the 'automatic' function.You are asking us to diagnose an unknown device and you are feeding us the clues one by one. Why don't you just give us all the information that you have. A photograph of each side of the board would be helpful.
please note, the contrast in this display is automatic and so pin 3 need not be connected. if an adjustment trimmer is provided it will have no effect