I need some help on how to hook up a autometer water temp gage.

OK I looked under the hood this moring and can only find the one temp sensor on the manifold. If I replace the stock sensor and the plug with the new one, how or what should I do about the stock plug? It has 2 wires going to it (the plug) one has to be going to the stock temp gage in the car what/where is the other one going? If it is going to the computer do I need it hooked up do the car runs correctly or will it run fine without it. My goal is to still have the stock gage on the dash working as normal and have the autometer gage working also. I need help on this would like to get I would like to get it finished this weekend if possiable.

 

is the gauge mechanical or electric?

 

It is electrical, I think I am going to find some parts to "T" into where the existing (stock) one is.