Textron JACOBSEN GP400, Technical/Repair Manual

Page: 91 / 354

ELECTRICAL
4252490-Rev A 4-39
4
Symptom: Engine temperature gauge indicates a temperature when the engine is cold.
Symptom: Engine temperature gauge does not indicate a temperature.
Symptom: Hour meter does not log hours.
Horn and Audible Alert Circuit
Symptom: Horn does not sound when horn switch is pressed.
Symptom: Horn does not sound during lamp and audible alarm check.
Symptom: Horn does not sound with engine oil pressure light on.
Symptom: Horn does not sound when engine temperature reaches overtemp.
Probable Cause Remedy
Faulty engine temperature sensor. Substitute the engine temperature sensor with a known good engine temperature sensor.
Faulty engine temperature sensor gauge. Substitute the engine temperature gauge with a known good engine temperature gauge.
Probable Cause Remedy
Faulty engine temperature sensor. Substitute the engine temperature sensor with a known good engine temperature sensor.
Faulty engine temperature sensor gauge. Substitute the engine temperature gauge with a known good engine temperature gauge.
Probable Cause Remedy
Faulty hour meter. Substitute the hour meter with a known good hour meter.
Probable Cause Remedy
Faulty horn switch. Test the horn switch. (See “Horn Switch Test” on page 4-44.)
Faulty horn. Substitute the horn with a known good horn.
Probable Cause Remedy
Faulty horn. Substitute the horn with a known good horn.
Insufficient circuit voltage. Simultaneously turn the key switch in the run position and check for approximately 12
volts at control module terminal J2-10. If the voltage is not approximately 12 volts,
diagnose the insufficient voltage issue.
Probable Cause Remedy
Faulty horn. Substitute the horn with a known good horn.
Insufficient circuit voltage. Turn the key switch to the run position; check for approximately 12 volts at control module
terminal J2-10. If the voltage is not approximately 12 volts, diagnose the insufficient
voltage issue.
Probable Cause Remedy
Faulty horn. Substitute the horn with a known good horn.
Insufficient circuit voltage. Turn the key switch to the run position; check for approximately 12 volts at control module
terminal J2-10. If the voltage is not approximately 12 volts, diagnose the insufficient
voltage issue.