I'm surprised that you have two wires to that single terminal, as I believe it is the (+) connection for your fuel gauge. My guess, looking at your wires, is that the green is going to the gauge, and the black is for ground but that is a pure guess. My sender, from AutoMeter, lands a single pink to the terminal shown, and a black to one of the screws holding the sender to the tank. That screw used for sender ground has to be clean, making good electrical contact. Does your fuel gauge work the way it's wired? If my guess is right you've got a dead short atop your sender right now, so you will have blown the fuse for your gauges.