No ignition lights,wont start

Hi,my name is dave ,i am a new member and have 2 hijets,both lpg 1 4x4,also have a extol.
I have a problem that i hope someone has come across before;I left ignition on the car by mistake for days the battery is flat,put a new battery on and it wont start turns over but does not fire,i only have 2 lights on dash(engine management and oil light)the petrol pump works when you turn ignition on.
I was changing the lpg tank and radiator if this makes any differance.Hope someone can help.

Check the 2 little wires on the live terminal.

Give them a wiggle.

cleaned it and still no joy,thanks though