My 1978 Ramcharger has the factory tach in the dash. It has three wires coming out the back and one terminal without a wire. The one terminal on the back with no wire I am guessing goes to the distributor as it has the letters 'dst' under it. Does anyone know what all these wires are for and where it hooks in to the distributor? Does 'dst' indeed need to be hooked to the distributor. With this RC, it is a great truck but some of the wiring has been unhooked. I am cleaning all this up and everything is working great so far. Thanks for any help.