I recently bought a 1976 280Z and the owner got the trans and engine swaped to what he thinks its off a 77 model the problem is that when I am in 4th gear the reverse lights come on and dont come one when I am in Reverse, whats the problem or where is the sensor I cant find it in the book. There is two sensors next to the drain and fill plug on the trans and one of them has the wires cut not sure what that sensor is for and neither does the owner. Help Please