I have a 2002 frontier 4cyl 5spd and the speedometer quit. the tach still works as do all of the other gauges. The check engine light came on as well. I put it on a lift and put it in gear and the wires leading to the speedo display varying voltage depending on the speed of the rear wheels. I dont know about the last wire(there are three total, goes to the ECU I assume). does anyone know what this wires voltage or resistance or whatever should be?