Turbocharger Electrical System Diagnosis

TURBO INDICATOR LAMP & WARNING LAMP OPERATION

1. Do both green indicator lamp and amber warning lamp light when ignition switch is turned ON?
2. If not, check the following:
a. Check 7.5 gauge fuse. If fuse is blown, check for short circuit and repair.
b. Check 7.5 amp charge and ignition fuse. If fuse is blown, check for short circuit and repair as required.
c. If gauge, charge and ignition fuses are not blown, check if discharge warning light is Off. If discharge warning light is On, charging system is faulty. If discharge warning light is Off, instrument cluster is faulty.
3. If green indicator lamp and amber warning lamp are ON when engine is idling, proceed as follows:
a. If both lamps stay On, ensure discharge warning lamp is Off. If not, charging system is defective.
b. If green lamp stays On, check for an open circuit in wire harness between low pressure switch and instrument cluster. If wire harness is satisfactory, low pressure switch is defective.
c. If amber lamp is On, check for an open circuit in wire harness between high pressure switch and instrument cluster and a grounded connection of switch. If wire harness is satisfactory, high pressure switch is defective.
4. If green indicator lamp and amber warning lamp are Off when engine is idling, proceed as follows:
a. Using a suitable hand held pressure pump and gauge assembly, apply 2.0 psi to both pressure switches. If green indicator lamp does not light, check for short circuit in wire harness between low pressure switch and instrument cluster. If wire harness is satisfactory, low pressure switch is defective.
b. If amber lamp illuminates, apply 10.4 psi on 1984 models or 11.9 psi on 1985-86 models to both pressure switches. If green indicator lamp lights with specified pressure applied to both pressure switches, instrument cluster is defective. If green indicator lamp does not light, high pressure switch is defective.
5. Apply 10.4 psi on 1984 models or 11.9 psi on 1985-86 models, to both pressure switches. If amber indicator lamp lights, turbocharger indicator warning operation lamp is satisfactory. If amber indicator lamp does not light, check for short circuit in wire harness between high pressure switch and instrument cluster. If wire harness is satisfactory, high pressure switch is defective.