Hi all,have a bad starting problem.the kids have left the door open on my vn and the battery has gone flat,and i was changing the battery over with another and i got a spark and now it is just starting and cutting out within a couple of seconds or just winding over and not attempting to start.I have changed over coil pack and have tried another ecu but the same thing is still happening.I have noticed there is a small box with two wires coming off which one wire is connected to the negative battery terminal and the other is just sitting down in battery floor.just wondering if this should be connected and where to.It has computer protector written on it and stops surging when jump starting,so i am thinking maybe i have knocked this off from another wire.Also the car is dual fuel and is not starting on either LPG or petrol.
Any help will be greatly appreciated.

thanks dave