AM Short Sweep Fuel gauge

[RBuhr69]

Question, I have the AM short sweep electric gauge for the fuel gauge. There are three wires for the factory gauge but there is only one slot on the AM gauge for the sendor signal.

So my questions is can i use the factory wiring in some sort of manner, or is there a sendor unit I need to purchase? I will be installing it all this Friday and want to be prepared if I should have ordered a sender or am I able to just use existing wiring...