Tachometer: Description and Operation

The tachometer is a 6000 rpm tachometer. It has four terminals: one labeled B (12 to 14.5V), one labeled S (EDIS tach signal in), and two labeled 6 (cylinder selection grounds). The bottom ground (6) terminal is grounded. The top ground (6) terminal is grounded through a 4.32K ohm resistor in a 6-cylinder engine vehicle and is connected directly to ground for an 8-cylinder engine vehicle.