Oil Pressure Gauge Calibration Test (1968-74)

When instrument voltage regulator or gauge is suspected of being out of calibration, having a fluctuating movement, or high or low pressure, both the gauge and IVR must be tested simultaneously. This test is done on the vehicle.

Test equipment consists of a 10 ohm resistor, 22.8 ohm resistor and a 73 ohm resistor. Disconnect lead from gauge at sender unit, and connect resistor between gauge lead and ground. Turn on ignition. With the 10 ohm resistor, gauge should show a high scale reading. With 22.8 ohm resistor, gauge should show a mid scale reading. With the 73 ohm resistor, gauge should show a low scale reading.

If gauge does not perform as prescribed, replace IVR and retest. If gauge now (with new IVR) reads correctly problem is solved. If gauge is still out of calibration it is defective and must be replaced.