Onan HGJAB Service Manual

11-4
STARTER ENGAGES – DISENGAGES
WARNING
Some genset service procedures present hazards that can result in severe personal injury
or death. Only trained and experienced persons with knowledge of fuels, electricity, and machinery
hazards should perform genset service. See Safety Precautions.
Logic: Cranking voltage dips below 6 VDC: microprocessor aborts start attempt
Possible Cause: Battery connections, battery, charging system, start/stop switches, engine compression
Diagnosis and Repair:
1. Measure battery voltage at battery and genset.
2. Inspect battery connections and cables for cleanliness, tightness and damage: clean, tighten and repair
connections and cables as necessary.
3. Check electrolyte level and hydrometer reading in maintenance type batteries: replace electrolyte and
recharge or replace battery as necessary.
4. Disconnect genset control P1 connector, verify P1 pins are fully inserted and inspect pin condition per
PSB–676: insert, repair or replace pins as necessary.
5. Reconnect P1 connector and test run genset for fault occurrence: repair or replace pins in connector as
necessary.
6. Measure battery voltage at genset while attempting to start from local or remote switch: recharge or re-
place battery if voltage drops below 9 VDC, test and service genset battery charger if so equipped, in-
crease battery cable size or run parallel cables.
7. Measure battery voltage and check for charger increase while genset is running.
NO AC POWER – GENSET RUNNING, STATUS LED ON STEADY OR FLASHING RAPIDLY
WARNING
Some genset service procedures present hazards that can result in severe personal injury
or death. Only trained and experienced persons with knowledge of fuels, electricity, and machinery
hazards should perform genset service. See Safety Precautions.
Logic: Genset control in normal or Engine Run Only mode
Possible Cause: Circuit breakers, Engine Run Only mode due to faulty generator
Diagnosis and Repair:
1. Status light on – Measure AC output at genset circuit breaker: reset or turn on genset circuit breaker, diag-
nose faulty loads as necessary
2. HGJAD, E, F Models – (Rapid flashing status light – Engine Run Only mode)
A. Remove connector P1 from control and re-install and try to start genset: inspect, repair or replace
P1 connector pins as necessary.
B. While running in Engine Run Only mode externally excite field with 12 VDC or 24 VDC and measure
main and quadrature winding AC output.
C. Measure field, quadrature and main winding resistance: clean slip rings, replace brushes, repair har-
ness and replace rotor or stator as necessary.
D. Measure field, quadrature and main winding resistance to ground: clean slip rings, replace brushes,
repair harness and replace rotor or stator as necessary.
E. Measure field, quadrature and main winding resistance to each other: clean slip rings, replace
brushes, repair harness and replace rotor or stator as necessary.
F. Check brush alignment per PSB-682a.

Onan HGJAB Specifications

General

Brand	Onan
Model	HGJAB
Category	Portable Generator
Language	English