Troubleshooting Hints - Instrument Cluster

PERFORM BEFORE BEGINNING SYSTEM DIAGNOSIS
1. Check LP Fuse #33. If open, check CKT 40 for short to ground.
2. Check LP Fuse #11. If open, check CKT 39 for short to ground.
3. Check any inoperative indicator bulb.
4. Make sure grounds G104, G106, G200 and G401 are clean and tight.
5. If Instrument Cluster is completely or partially inoperative, check CKT 39 and CKT 439 for an open.
^ Check for a broken (or partially broken) wire inside of the insulation which could cause system malfunction but prove "GOOD" in a continuity/voltage check with a system disconnected. These circuits may be intermittent or resistive when loaded, and if possible, should be checked by monitoring for a voltage drop with the system operational (under load).
^ Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems (refer to General Troubleshooting Procedures). Diagnostic Aids
^ Refer to System Diagnosis.

"Oil" Pressure Indicator Diagnosis
If the "OIL PRESSURE" Indicator stays "ON" with die Engine running:
^ Disconnect Fuel Pump Switch and Engine Oil Pressure Gage Sender. If the indicator goes "OFF," replace sender. If the indicator stays "ON," check CKT 31 for short to ground.
^ Inspect the Instrument Cluster printed circuit for a short. Also check that the printed circuit is mating properly with its connectors and not shorted there.

If the "OIL PRESSURE" Indicator does not come "ON" before the Engine starts, and the bulb is good, measure the resistance from the Fuel Pump Switch and Engine Oil Pressure Gage Sender connector to ground.
^ If the resistance is approximately 1 ohm or more, check CKT 31 for an open.
^ Connect a fused jumper between Fuel Pump Switch and Engine Oil Pressure Gage Sender connector terminal "A" and ground. If the indicator comes "ON," replace the sender. If the indicator stays "OFF," remove Instrument Cluster for repair.
^ Check that the printed circuit has no cracks or flaws and is mating properly with its connector.

"Hot" Coolant Temperature Indicator Diagnosis (Coolant Temperature Gage "Normal")
If the Coolant "HOT" Indicator comes "ON" with the Engine running, but not overheated:
^ Check the Instrument Cluster printed circuits for shorts to ground. If OK, service Instrument Cluster.

If "HOT" Coolant Temperature Indicator does not come "ON" while starting the Engine, and the bulb is good:
^ Ground CKT 135 at Ignition Switch connector C1 terminal "C." If the indicator comes "ON," the circuit is good. Replace the Ignition Switch.
^ If the indicator does not come "ON," check the Instrument Cluster printed circuit for an open. If OK, service Instrument Cluster.