Oil Pressure Gauge

Gauge indicates engine oil pressure when ignition switch is in RUN position. Pointer is moved by 2 magnetic coils which pull on pointer in opposite directions. One coil is grounded through fuel pump/oil pressure switch/sender which varies its resistance in relation to engine oil pressure. When oil pressure is low, resistance is low, and when oil pressure is high (about 80 psi), resistance is high (about 90 ohms).