Yingang YG48Q-5A, Maintenance Manual

Page: 127 / 144

YG48Q-5A
Maintenance ManualIllumination signal system
140
Major faults diagnosis
Phenomenon Possible causes Solutions

Headlamp does not
illuminate;

Hi-beam does not
illuminate

Low-beam does not
illuminate

Both do not illuminate

Accumulator voltage too low;

Corresponding fuse is not connected or is
blown;

Corresponding switch failed;

Bulb failure;

Poor plugging of line;

Related lines of the main cable are open

Recharge the accumulator;

Connect the fuse or replace it;

Repair or replace switch;

Replace bulb;

Re-plug;

Repair or replace main cable.

Headlamp fails to
illuminate reliably

Poor contacting in fuse, bulb or lines;

Reconnect the poorly contacted
parts;

Headlamp illumination
small

Accumulator voltage too low;

Line contact voltage drop too large;

Headlamp body failed

Recharge the accumulator;

Repair the line;

Replace headlamp
 Position lamp doesn’t
illuminate:

Front position lamp
doesn’t illuminate:

Sidecar front / rear
position lamp

Tail lamp doesn’t
illuminate;

Both do not illuminate

Corresponding fuse is not connected or is
blown;

Position lamp switch failed;

Bulb failure;

Poor contact in lines;

Related lines of the main cable are open

Connect the fuse or replace it;

Repair or replace the left switch;

Replace bulb;

Re-plug;

Repair or replace main cable.

Brake lamp does not
illuminate

Corresponding fuse is not connected or is
blown;

Front brake lamp switch failed;

Rear brake lamp switch failed;

Bulb failure;

Line failure

Connect the fuse or replace it;

Replace front brake lamp
switch’;

Adjust and replace rear brake
lamp switch;

Replace bulb

Inspection / Repair

Horn does not sound

Corresponding fuse is not connected or is
blown;

Horn button failed;

Horn failed;

Poor contact in lines;

Related lines of the main cable are open.

Connect the fuse or replace it;

Repair or replace the left switch;

Adjust or replace horn;

Re-plug;

Repair or replace main cable.

Turn signal lamp does
not illuminate;

Front turn lamp does
not illuminate;

Rear turn lamp does
not illuminate;

Both do not illuminate

Accumulator voltage too low;

Corresponding fuse is not connected or is
blown;

Left turn lamp switch failed;

Right turn lamp switch failed;

Flasher failed;

Bulb failure;

Poor contact in lines;

Related lines of the main cable are open.

Recharge the accumulator;

Connect the fuse or replace it;

Repair or replace the left switch;

Repair or replace the left switch;

Replace flasher;

Replace bulb;

Re-plug;

Repair or replace main cable.