Sym Citycom.300i, Service Manual

Page: 242 / 270

17. Electrical System
17-3
Trouble Diagnosis
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 voltage regulator
No spark produced by spark plug

The spark plug is out of work

The cable is poorly connected, open or
short-circuited

Between AC Generator ECU
 Poor connection between ECU and ignition coil

Poor connection between ECU and the main
switch

Bad main switch
 ECU malfunctions

AC Generator malfunctions
Starter motor does not work

The fuse is blown
 The battery is not fully charged

Bad main switch

Bad starter switch

The front or rear brake switches does not
function correctly
 Starter relay is out of work

The ignition coil is poorly connected, open or
short-circuited

The starter motor malfunctions
Intermittent power supply

The connector of the charging system becomes
loose

Poor connection of the battery cable
 Poor connection or short-circuit of the
discharging system
 Poor connection or short-circuit of the power
generation system
Charging system does not operate
properly
 Burnt fuse

Poor contact, open or short circuit
 Regulator/Rectifier malfunctions

AC Generator malfunctions
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
-
AC Generator malfunctions
- Improper installation of CPS
- ECU malfunctions
Weak starter motor

Poor charging system

The battery is not fully charged
 Poor connection in the windings

The motor gear is jammed by foreign material
Starter motor is working, but engine does
not crank
 Poor starter motor pinion

The starter motor runs in reverse direction
 Poor battery
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