In this application, oil pressure switch in the fuel pump circuit, oil pressure can't shut off the relay.
The relay has two circuits, the coil side of relay and the load side of relay. The pcm supplies voltage, green wire with white tracer, to coil side of relay during initial prime and if there is an rpm signal, voltage continues during crank and run. The ground for coil side of relay is constant. When the relay is energized, the arm for load side switches to voltage which is hot all the time, ecm B fuse. The o/p switch and load side of relay gets voltage from the same fuse.
Tuesday, October 19th, 2010 AT 8:56 AM