After bonding on my front wing after if flew off (not the first time) and soldering the wires back together, the light does not work. Does it matter which wire is the earth, and which is the power ? I have checked with a multimeter and get power to the inside of the fixing, and the earth is good. The only other thing that I can think of, is that the fixing is not connecting to the bulb correctly after its bid to break free ?