Here is some info from the Factory Service Manual.
If an individual gauge is inoperative, see the diagnostic
procedure under the heading for that gauge. If
more than one gauge in the main cluster or gauge
package cluster is inoperative, perform the following:
(1) Check fuse 9 in the fuseblock module. If OK, go
to next step. If not OK, replace fuse.
(2) Check for battery voltage at fuse 9 with ignition
switch in ON position. If OK, go to next step. If
not OK, repair open in circuit from ignition switch
and/or refer to Group 8D - Ignition Systems for testing
of ignition switch.
(3) Turn ignition switch to OFF. Disconnect battery
negative cable. Remove the affected instrument cluster
bezel and cluster assembly. Disconnect the cluster
(4) Connect battery negative cable. Turn ignition
switch to ON. If problem is in main cluster, check for
battery voltage at cavity 3 and cavity 19 of main
cluster connector. If problem is in gauge package
cluster, check for battery voltage at cavity 2 and cavity
12 of gauge package cluster connector. If OK, go
to next step. If not OK, repair open in circuit from
fuse 9 as required.
(5) Turn ignition switch to OFF. Disconnect battery
negative cable. Probe cavities 14 and 20 of main cluster
connector, or cavities 1 and 13 of gauge package
cluster connector. Check for continuity to a good
ground. There should be continuity. If OK, replace
the cluster printed circuit. If not OK, repair open in
circuit as required.