i got a oil temp gauge and need some help with it. theres 5 sonnections i figured out all the wires except the S, which i assume is for signal(kinda obvious), i know it needs a oil sender unit. is there any praticular type to use or will and sending unit work? is there any way just to tap into the stock sending unit wire or is an after market one required along with the stock one like is shown on neons.org with a "T" fiting on the back of the block?