Fuel Pump Connections

Hello, I took ownership of a 1992 Stanza that sat rotting in a yard for a few years. Everything runs fine now except for the fuel guage and light do not work. Before assuming the sending unit or guage was bad i took a look under the fuel pump access cover. There were 2 wires rusted off underneath a black wire and a yellow/green wire with what looks like a location to connect in the second pump cover. The yellow/green measures B+ and the black is a ground to the low fuel light. There was very little gas in the tank, (as it was drained because of the age) and the light should have lit. After connecting the two I added about 3 gallons to the tank and the light stayed lit. I am assuming the two wires aren't supposed to connect to each other. However reguardless of how the yellow/green or black wire, was hooked up to the pump I still had a dead guage and light. Is it safe to assume the sending unit is bad and does anyone have a wireing schematic of the fuel system?

-Mark