Sym HD2 125 - Troubleshooting

18. ELECTRICAL SYSTEM
18-3
Troubleshooting
No voltage
● Battery discharged
● The cable disconnected
● The fuse is blown
● Improper operation of the main switch
Low voltage
● The battery is not fully charged
● Poor contact
● Poor charging system
● Poor regulator rectifier
No spark
● Poor spark plug
● The cable is poorly connected, open or
short-circuited
● Poor connection between ECU and ignition coil
● Poor main switch
● Poor ECU
● Abnormal AC Generator
Starter motor does not work
● The fuse is blown
● The battery is not fully charge
● Poor main switch
● Poor starter switch
● The front and rear brake switches do not
operate correctly
● Starter relay is out of work
● The ignition coil is poorly connected, open or
short-circuited
● The starter motor is out of work
Intermittent voltage
● The connector of the charging system becomes
loose
● Poor connection of the battery cable
● Poor connection or short-circuit of the charging
system
● Poor connection or short-circuit of the power
generation system
Abnormal charging system
● Burnt fuse
● Poor contact, open or short circuit
● Poor regulator rectifier
● Poor AC Generator
Engine does not crank smoothly
● Primary winding circuit
- Poor ignition coil
- Poor connection of cable and connectors
- Poor main switch
● Secondary winding circuit
- Poor ignition coil
- Poor spark plug
- Poor ignition coil cable
- Current leakage in the spark plug
● Incorrect ignition timing
- Poor AC Generator
- Improper installation of CPS
- Poor ECU
Weak starter motor
● Poor charging system
● Battery is not fully charged
● Poor connection in the windings
● The motor gear is jammed by foreign material
Starter motor works but engine does not
crank
● Poor starter motor pinion
● The starter motor run in reverse direction
Abnormal battery
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