Fuel Level Indicator (1968-74)

Disconnect wiring connector from terminals at sender unit. Check terminals for possible corrosion or undercoating, and clean as necessary. Connect lead of a 12 volt test light, or positive lead of a voltmeter to gauge lead that was disconnected from sender. Connect other test lead to a good ground. With ignition on, a flashing light or fluctuating voltmeter will indicate instrument voltage regulator is operating and that gauge indicator circuit is not interrupted. If light stays on, or voltage reading is steady, replace IVR. If no voltage is indicated by meter or test light, check IVR for proper ground, or open circuit across IVR. Do not ground or spark either terminal of IVR, this could burn out dash wiring harness of IVR, or both.