Getting ready to start the re-wire of my 67 Bird. All new harnesses. Since I'll be using gauges that have built in warning lights for oil pressure and water temp the stock wires for the original sensors won't be used. Looking at the wiring diagrams it appears that the sensors were a ground source for the factory warning lights. If this is true wouldn't those have a 12 volt ign/keyed source I could use as a trigger for a relay??