jcb G20, Operator'S Manual

Page: 143 / 177

Maintenance
Fault-Finding
136 9831/0650-3 136
Table 65. Open Circuit Injector
Step Trouble Action/Remedy
Perform the injector buzz test, if the injector is faulty it will not
produce a buzzing sound. In such instances raise Techweb
Helpdesk call.
1 Pressure diagnostics fault
If no fault is found proceed to step 2.
Check the resistance of injector.
– For solenoid, it should be less than 1 Ohm.
If the resistance is incorrect, change the injector and calibrate
it.
2 Injector connection fault
If no fault is found proceed to step 3.
Check the harness continuity and electrical insolation, re-
pair/replace as necessary.
3 Wiring fault
If no fault is found raise Techweb Helpdesk call..
Alternator
Table 66.
Cause Remedy
Substitute fuse.
Increase speed by 15%.
Alternator does not excite
For an instant apply on "+" and " -" of the electronic
regulator a 12 V battery voltage with a 30 resistor in
series, respecting the polarities.
After being excited alternator does not excite Check connection cables as per attached drawings.
Reset voltage potentiometer.
Check speed.
Low voltage at no load
Check windings.
Reset voltage potentiometer. High voltage at no load
Substitute regulator.
Reset the voltage potentiometer.
Current too high, power factor lower than 0.8, speed
lower than 4% of rated speed.
Substitute regulator.
At load conditions, voltage lower than rated voltage
Check diodes, disconnect cables.
Calibrate the voltage. At load conditions, voltage higher than rated voltage
Replace the controller.
Check uniformity of rotation. Unstable voltage
Regulate stability of regulator by acting on STAB po-
tentiometer.
Control Panel
Starting
Table 67.
Symptom Possible Remedy
Check the battery and wiring to the unit
Check the DC supply
Unit is inoperative. Read/Write configuration does not
operate
Check the DC fuse
Unit shuts down Check DC supply voltage is not above 14.7V or be-
low 9V Volts