I have the engine 302 5.0 HO fuel injected out a 1980 Continental Mark Vl. It has two sending unit locations on the drivers side front of the manifold about three or four inches apart. The front one has two wires attached too a single post top. The second one has a snap on top with two tan wires coming out of it. I’m not getting a temp guage reading on it now or when I ground either of the four wires and turning my pickup to accessory. Can someone tell me what these two locations should be running too. I know I have to put in a new sending unit to make my aftermarket guage work, but I don’t want to remove the wrong one. Your help will be greatly appreciated.