Dongfeng DFA1063DJ10 (14)-301/303. Manual - part 31

Electric System

EL-5

General Instruction

Constitution      

Power supply division: Alternator, battery

Starting system

Power supply warning system

Instrument indicator system

Lighting system

Others: Wiper, horn, cigar lighter, radio cassette player

Features

Using integrated alternator

Using electromagnetic main power switch

Two fusible wires at starter

22-way fuse box

The complete truck wiring

The wires of 22-way fuse box of the complete truck are connected as follow

 In the normal conditions, the output of alternator reaches ignition switch, lighting and instruments by the

way of two fusible wires. If the alternator fusible wires are burnt, the above systems will continue to operate using
the battery power. But if the engine stops at the time, the systems can't start until replace the fusible wires. The
fusible wire must be replaced immediately to prevent the battery from over discharging.

Bedsides the safety control described above, there are another 6 small relays: start relay, ignition relay, heater

relay, A/C relay, radiator relay, and horn relay.

Electric  System

EL-6

Battery 

Specifications

Check

1.Electrolyte density when fully charged: 1.26~1.285g/

cm³

①

Density meter

②

Floater

2.Fill distilled water in time if the electrolyte is found

insufficient. Charging for over half an hour after filling
in order to let the filled distilled water fully fix with the
former electrolyte.

Electrolyte level (above the top of the battery plate)

15~20mm

①

Battery plate        ② Electrolyte

Battery

Two batteries 6-QW-90DF are in series

Type

Less maintenance

Nominal voltage (V)

12

Nominal capacity (A · h)

165

Electric System

EL-7

Alternator

Alternator operation principle diagram

Specification

Construction Principle

Features

Improve the magnetic circuit and use 8-diode rectifier to increase the output power.

Construction without brush to make it simplified, and ease of servicing

Use the alternator with built-in rectifier and electric regulator.

Operation principle

The alternator produces self-excitation field and operates normally when the charging indicator lamp is

extinguished.

Vehicle model

   EQ1074T/G5AD-666

Nominal voltage (V)

28

Adjusting voltage (V)

28 ± 0.3

Nominal current (A)

45

Nominal revolution （r/min）

6000

Starting revolution （r/min）

＜

1150

Output current (A)

18-20

1.Battery
2.Electric using equipment

3.Charging indicator
4.Regulator

Electric  System

EL-8

Trouble analysis

Note:
The self-excitation speed is very low (about 1000r/min) with battery operation. So be sure to see if the charg-

ing indicator is perfect or not during the operation.

Alternator negative earthing.
Be sure to use the original factory's parts as possible if it has to replace the diode.
During the alternator operation, if the temperature of the casing reaches to 105℃＋ambient temperature, and

the output of the alternator is normal, the alternator is not burnt down.

Trouble

Cause

Method

Charging indicator does not 
extinguish and the truck 
starts difficultly during 
operation

Short circuit or too large contact resistance

Check the circuit and 

repair or replace the 

damaged parts

Short circuit between the 3 phases and rotor winding and 
casing

Diode damaged

Regulator failed

Charging current is too 
small, the battery is insuffi-
cient. No charging at low 
speed.

Output voltage is over low.

Exclude the trouble 

and replace the dam-

aged parts

Diode is partly damaged

The rotor winding has 1 phase or 3 phases bad contact

Slipping belt

The instrument indicator 
sometimes charges and 
sometimes not

Belt is too loose and slippery.

Tighten the contac-

tors, and replace the 

instrument if it is dam-

aged.

Built-in regulator works abnormally

The contact from engine fire wire connector to battery 
connector is loose

Alternator interior connection is loose.

Instrument failed

Engine has abnormal noise 
during running.

Belt is loose or worn, shaken during running

Adjust the belt, 

replacebearing

Bearing damaged or too large clearance

Too large clearance of bearing caused interference