A: Display Partially Illuminated or Completely Black
A1 CHECK HEADLAMP SWITCH (DIMMER)
^ Turn headlamps on.
^ Rotate headlamp switch.
^ Does instrument cluster dim properly?
Yes
GO to A2.
No
REPLACE headlamp switch.
A2 CHECK FUSES
^ Check Circuits 797 and 298 for blown fuses (battery and run voltage to cluster).
^ Do fuses check OK?
No
GO to A3.
Yes
GO to A4.
A3 CHECK FOR SHORTS
^ Turn ignition switch lock cylinder to the OFF position.
^ Disconnect battery ground cable
^ Connect Rotunda Digital Volt-Ohmmeter 014-00407 or equivalent from circuit with blown fuse to ground.
^ Is there continuity?
No
REPLACE fuse.
Yes
SERVICE circuit as required.
A4 CHECK FOR POWER TO FUSE
^ Connect battery.
^ Turn ignition switch lock cylinder to RUN position.
^ Measure voltage from Circuits 797 and 298 to ground.
^ Is the voltage greater than 9V?
Yes
GO to A5.
No
SERVICE open in fuse holder.
A5 CHECK FOR LOOSE CONNECTIONS
^ Turn ignition switch lock cylinder to OFF position. Remove instrument cluster (leave connected).
^ Turn ignition switch lock cylinder to RUN position.
^ Wiggle A and B connectors on rear of instrument cluster
^ Are connector(s) OK?
No
SERVICE as required.
Yes
GO to A6.
A6 CHECK POWER AND GROUND
^ Turn ignition switch lock cylinder to OFF position.
^ Remove instrument cluster.
^ Turn ignition switch lock cylinder to RUN position.
^ Measure voltages at the harness connector A and B of the cluster.
^ Voltages should be: Pin B (B+ function) battery voltage Pin B (Run function) battery voltage Pin A (Run function) battery voltage
CAUTION: Before checking the continuity of any circuit, make sure there is no voltage present in the circuit prior to switching the test equipment to the resistance function to avoid damage to equipment. Refer to the test equipment user's manual for additional information.
^ Check continuity of ground circuit pins 8B and 13A to battery ground.
^ Do circuits check as outlined?
Yes
REPLACE instrument cluster.
No
SERVICE Circuit
B+ No.54
RUN No.489
GROUND No.397.