Truck Repair: tachometer, drive oil, computor

Question
i am working on 1997 for sterling with a N14 cummings and the tachometre is not working .can you please tell me if there  is a sensor or is it connected through the ecm

Answer
Most of the newer OEMs use the computor ECM.Try checking the EPS sensor that is located between the Accy drive & oil pump.Remove it & visually check it to make sure that the black plastic is not protruding past the gold metal housing.Then if that is good ohmn out the 2 outside & 2 inside wires.Should be between 1000-2000 ohmns.