Onan HGJAB Service Manual

11-3
NO RESPONSE – STATUS INDICATOR LIGHT DEAD
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: To start – control receives ground via start/stop switch to start or stop input on control
Possible Cause: Low/No battery voltage, poor battery connection, faulty battery, open harness connection,
faulty start/stop switch, faulty LED
Diagnosis and Repair:
1. Measure battery voltage at battery, at genset and at connector P1: reconnect, clean, repair and replace
connections as necessary.
2. Measure battery voltage at genset while attempting to start or prime from local or remote switch: recharge
or replace battery if voltage drops below 9 VDC, test and service genset battery charger if so equipped,
increase battery cable size or run parallel cables.
3. Measure for continuity change across start/stop switch between neutral and start position and neutral and
stop position at switches and at connector P1: reconnect or repair connections, replace switches as nec-
essary.
4. Test switches LED by energizing with 12 VDC: replace switches as necessary.
5. 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.
6. Reconnect P1 connector and test run genset for start and prime operation: replace control as necessary.
STARTING BATTERIES RUN DOWN
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: Low/No battery voltage
Possible Cause: Battery connections, battery, charging system, excessive cranking, excessive priming
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. Verify battery charger is on and check operation.
5. Measure battery voltage and check for charging increase while genset is running.
6. Check last fault and record: troubleshoot as necessary.
7. 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.
8. Reconnect P1 connector and test run genset for fault occurrence: repair or replace pins in connector as
necessary.
9. Measure for continuity change across start/stop switch between neutral and stop position at switches and
P1 connector: replace switches as necessary or disconnect external stop device if so equipped.
10. Measure for voltage at fuel pump while genset is not running or being primed: replace control as neces-
sary.

Onan HGJAB Specifications

General

Brand	Onan
Model	HGJAB
Category	Portable Generator
Language	English