Fuel Gauge & Sending Unit

WARNING: This page is about a different car, the 1995 Jeep Wrangler. However, it is still accessible from the selected car via links, so may be relevant.

Turn ignition switch to ON position. Disconnect fuel gauge sending unit connector (connector is located near left front upper corner of fuel tank). If gauge reads at high end of scale, go to next step. If gauge does not read at high end of scale, go to step 4).
Connect a jumper between terminals No. 1 and 2 of body half of fuel gauge sending unit connector. See Fig 1 . If gauge reads at low end of the scale, replace sending unit. If gauge does not read at low end of scale, go to next step.

Fig 1: Identifying Fuel Gauge Sending Unit Connector
Courtesy of CHRYSLER CORP.
Turn ignition switch to OFF position. Disconnect negative battery cable. Check for continuity between terminal No. 1 in body half of fuel gauge sending unit connector and ground. If there is continuity, go to next step. If there is no continuity, repair circuit to ground as required.
Remove center instrument cluster bezel and gauge package cluster assembly. Disconnect cluster connector.
Probe cavity No. 6 of cluster connector. Check for continuity to ground. If there is no continuity, go to next step. If there is continuity, repair short circuit as required.
Still probing cavity No. 6 of cluster connector, check for continuity to cavity No. 2 of sending unit wiring body half connector. If there is continuity, replace gauge. If there is no continuity, repair open circuit as required.

NOTE: If problem is related to gauge accuracy, confirm problem is gauge and not engine oiling system. Using a test gauge, determine actual engine oil pressure, to be compared to gauge readings, before proceeding with other testing.