Yes the IVR can be mounted anywhere you choose but must be chassis grounded. Out of the IVR is 5 volts. You must add a wire for it since you dont have one. What color the wire casing is makes no difference. It should go to the fuel gauge post at top center, not the 12 volt post, not the sender post. If that post has a odd metal clip instead of a nut, the wire can be put on the temp gauge stud that is on the same printed circuit. The printed circuit will carry 5 volts back to the fuel gauge. Lets try to not make this more complicated.