Symptom Related Diagnostic Procedures

SYMPTOM ACTION

Cluster displays do not illuminate ^ Check for blown fuses, and check
after the vehicle is started. for battery and ignition voltage at the
instrument cluster.

^ Check the ground from the instrument
cluster electrical connector to the instrument
panel ground stud.



Fuel, Oil, and Temperature gauges read ^ Check for disconnected pull-up module
maximum, and remain at maximum after electrical connector in the back of the
vehicle is started. electronic cluster.



Speedometer and odometer are inoperative. ^ Check the speed sensor or speed sensor wiring.
(a) Check the speed sensor operation.

(b) If the speed sensor is defective,
replace it. If the speed sensor is OK,
check the wiring to the speed sensor.
^ If the speed sensor and wiring are OK, check
the speedometer cable.



Oil, Fuel, or Temperature gauges inoperative. ^ Check for defective sending unit, sensor,
or wiring.
(a) Sending units and wiring can be
checked by grounding the connector
leads, at the sending unit, in the
vehicle.
(b) With the ignition switch ON, grounding the
connector leads will cause the oil, fuel, or
temperature gauges to read maximum.



Cluster display does not dim when headlamp ^ Check fuses in headlamp circuit.
switch is activated and rheostat rotated. ^ Check for loose connections or defective wiring
from headlamp switch to electronic cluster.
^ Check for defective headlamp switch.
NOTE: The electronic cluster requires both a marker
feed and an illumination feed to operate correctly.



Tachometer inoperative. ^ Check wiring from EFI power module to electronic
cluster (engines w/EFI).