The electrical system of the MAZ vehicle has a rated voltage of 24 V. The on-board network of the vehicle is made according to a single-wire circuit

The negative terminal of the batteries (AB) is connected to the vehicle ground through the mass switch (frame, power unit, generator and cab). The AB positive terminal is connected to the vehicle's on-board network through the main 60 A fuse.

Two-wire connected:

  • —portable lamp socket in cockpit
  • - cockpit lights
  • —heater fan motors
  • - independent heater
  • - tachograph

The main fuse is designed to protect the battery and generator from short circuit and polarity reversal when the engine is started from an external source and is not further considered as a fuse. (On vehicles with MAN engines, the 60 A fuse is shunted with a jumper with a cross section of 2.5 mm 2, therefore, it does not perform the functions of protection against short circuits (short circuit) and polarity reversal, but is used as a connecting panel for wiring) .

From the 60A fuse (on the side of the generator connection), all consumers of electricity are powered (with the exception of the alarm, which is connected directly to the battery) and additionally have their own fuses.

The starter and instrument switch, the main light switch, the starter relay and the ground switch winding are not fused.

All fuses are located in three blocks:

  • - fuses 60 A and 30 A, 1 each - in block 111.3722
  • fuses 6 A - 21pcs - in fuse and relay boxes 23.3722; 23.3722-01; 23.3722-02; 23.3 722-03
  • - fuses 16 A - 1 pc. and 8 A - 9 pcs. - in the fuse box PR 112.

The purpose of the fuses (stripped circuits) and their ratings are shown in the tables:

Assignment of fuses in block 111.3722

60 A - main fuse

30 A - power supply for an independent heater, PZD technological equipment

Assignment of 6 A fuses in fuse and relay boxes 233722, 233722-01, 233722-03

No. - No. - wires - power circuit

  • 1 - 127 - Parking brake warning lamp relay, voltage indicator, speedometer, tachograph
  • 2 - Sound signals
  • 3 - 57 - Stop signals
  • 4 - 90 - Windshield wiper, washer
  • 5 - 120 - Reversing lights, inter-axle and inter-wheel locks, engine light, semi-trailer steering axle lock, hitch light
  • 6 - 162 - Mirror heaters, trailer lights
  • 7 - On-board control system power supply
  • 8 - P51 - Instrument lighting
  • 9 - 55 - Fog lights
  • 10 - Cch.52 - Marker lights, right
  • 11 - D.52 - Side marker lights, left
  • 12 - Ф.56 - Dipped beam (left headlight)
  • 13 - F.56 - Dipped beam (right headlight)
  • 14 - 53 - Additional driving lights
  • 15 - K.54 - High beam (right headlight)
  • 16 - Z.54 - Main beam (left headlight)
  • 17 - D.80 - Heater fan
  • 18 - F.79 - Alarm
  • 19 - K.78 - Direction indicators
  • 20 - P.31 - Pilot lamps, indicators (instruments) of the main shield
  • 21 - 50 - Rear fog lights

Assignment of fuses in block PR 112

denomination

№ п

Power circuit

1

16 А

 

Reserve, technological equipment

2

valve

cooling fan clutch

3

Г.172

Body lighting.

control block Heater 15.8106-01 or Webasto

4

Кч.179

Fuel heaters

5

Р.171

Radio, timer

6

Г.59

Cabin lights

7

3.131

Portable lamp socket in the cab,

pneumosignal, refrigerator

8

 

Reserve

9

С.133

Level sensors, air dryer,

additional instrument panel, technol. Obor.

10

О.161

Engine stop valve

Assignment of relays located in blocks 23.3722, 23.3722-01, 23.3722-02, 23.3722-03

Relay type 901.3747-11

Relay No. - Consumers

  • K1 - Sound signals
  • K2 - Reversing lights
  • K3 - Blocking of the "ground" switch
  • K4 - Brake lights
  • K5 - Onboard control system 23.3722, 23.3722-02
  • K6 - Dipped beam headlights
  • K7 - Blocking additional high beam headlights
  • K8 - Marker lights
  • K9 - Driving lights
  • K10 - Electric torch device (resistance shunt)
  • K11 - Electric torch device (generator blocking)

Location of electrical equipment

Name - Location

Sensor for turning on the control lamp for blocking the cross-axle differential VPST (MM 125D) - On the beam of the middle and rear axles

Sensor for switching on the cross-axle differential lock (MM 125) - On the pneumatic cylinder for switching on the middle axle lock and transfer case

Valve for switching on the cross-axle differential lock KEM-07 (P30.131.01) - On the left side member in the area of ​​the rear axle

Valve for switching on the center differential lock KEM-07 (P30.131.01) - On the left side member in the area of ​​the middle axle

Sensor for turning on the parking brake warning lamp DADV (MM124D) - On the two main parking brake drive valves

Sensors aemergency air pressure in the pneumatic brake system DADV (MM124D) - On the receivers of the front and rear circuits of the pneumatic system or on the sensor brake block

Air pressure sensors in the pneumatic system of the brakes MM370 - On the receivers of the front and rear circuits of the pneumatic system or on the block of brake sensors

Brake signal sensors - VPST (MM125D) - On the brake valve, on the trailer brake control valve or on the brake sensor unit

Engine stop solenoid 15.3747, PC330 - Outside, on the front panel of the cab, on the left under the lining

Pneumatic signal solenoid valve 16.3741 - Outside, on the left base of the cab

Relay of turns RS951A, PEUP6 - In the cab under the additional instrument panel

Wiper motor 13.5205 - Inside the cab, on the front of the cab, on the right

Washer motor - On the washer reservoir

Fuse and relay box 23.3722; 23.2722-01; 23.3722-03; 23.3722-04 - In the cab, in the central part, under the hinged panel cover

Wiper breaker relay 461.3747 - On the fuse and relay box

Range interlock relay 6312.3747 - In the cab on the right, under the flap of the instrument panel, under the flap of the fuses and relays

Fuse box Pr112 - In the cab on the right, under the hinged cover of the instrument panel.

Fuse box 111.3722; Starter relay 738.3747-20; Additional resistance EFU_12.3741000; Lantern FP12G; Relay signaling device 733.3747-10; Relay-interrupter of a control lamp of a parking brake RS493; Portable lamp socket - On the hinged fuse and relay panel

Electrical connectors (connecting the tail light harnesses) - In the junction box, at the rear of the left side member

Electrical connectors (connecting the side turn signal harnesses) - Inside the instrument panel on the left and right

Electrical connectors (connecting the side marker harnesses) - In the junction box, at the rear of the left side member

Electrical connector X62 (battery switch connection) - In the battery container

Scheme of electrical connections is "here"

Possible malfunctions of electrical equipment and solutions

Cause (Remedy)

Beeps don't work:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

- Faulty steering column switch

Check the function of the switch, replace if necessary

- Faulty switching relay

Check that the relay is working, replace the relay if necessary

- Sound signals are faulty

Check signal functionality, replace if necessary

Cab light does not work:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuses. If the fuse is defective, repair the short circuit in the circuit, replace the fuse. Replace pump

The engine light does not work:

- open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check that the fuse is working; if the fuse is defective, eliminate the short circuit in the circuit, replace the fuse

- Faulty light switch

Check the function of the switch, replace if necessary

- Destruction of the filament

Replace lamp

Pneumatic signal does not work:

- Open circuit of the valve, short circuit. Defective steering column switch

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

- Faulty valve

Check the condition of the valve, replace if necessary

Mirror heating not working:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse. If the fuse is defective, eliminate the short circuit in the circuit, replace the fuse.

- Faulty mirror heating switch

Check the function of the switch, replace if necessary

- Faulty heating element

Check the operation of the heating element, if not need - replace

Reversing lights not working:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness.

- Faulty reverse signal switch

Check sensor performance, replace if necessary

- Faulty switching relay

Check that the relay is working, replace the relay if necessary

- Destruction of the lamp filament

Replace lamp

The cross-axle differential lock valve does not work:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

- Faulty switch

Check the function of the switch, replace if necessary

- Faulty valve

Check valve operation, replace if necessary

The center differential lock valve does not work

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

Brake lights not working:

- Faulty switch

Check the function of the switch, replace if necessary

- Faulty valve

Check valve operation, replace if necessary

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

- Faulty brake light switch

Check sensor performance, replace if necessary.

High or low beam headlights and the corresponding control lamps do not work:

- Faulty switching relay

Check relay performance, replace if necessary

- Destruction of the lamp filament

Replace lamp

The main light switch is faulty. Steering column switch faulty:

  • Check the reliability of the contact in the detachable connections.
  • Check the integrity of the wiring harness.
  • Check the fuse is good. If the fuses are defective, eliminate the short circuit in the circuit, replace the fuse
  • Check if the switch works, replace if necessary

- Open circuit, short circuit

Check the function of the switch, replace if necessary

The marker lights do not work**:

- Faulty switching relay

Check relay performance, replace if necessary

- Destruction of the lamp filament

Replace lamp

- Faulty main light switch

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

- Open circuit, short circuit

Check the operation of the switch, replace if necessary

Rear fog lights and warning lamp do not work:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuses. If the fuses are faulty, eliminate the short circuit in the circuit, replace the fuse

- The main light switch is faulty.

Check the operation of the switch, replace if necessary

Faulty rear fog light switch:

- Destruction of the lamp filament

Check the function of the switch, replace if necessary

Replace lamp

- Faulty switching relay

Check that the relay is working, replace the relay if necessary

- Destruction of the lamp filament

Replace lamp

Turn indicators not included:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness.

- Faulty steering column switch

Check the operation of the switch, replace it if necessary

- Faulty relay breaker The PC951 relay has automatic short circuit protection (short circuit). When shorted in one of the sides, the relay turns off the direction indicators

PEUP6 has four independent channels: LB of the tractor, LB of the tractor, LB of the trailer, LB of the trailer. In the event of a short circuit in one of the channels, the rest remain operational

Check the operation of the breaker relay, if necessary, replace it

- Faulty alarm switch

Check the operation of the emergency switch, if necessary, replace it

- Destruction of the lamp filament

Replace lamp

The control lamps of the direction indicators of the tractor or trailer do not light when the PC95IA relay is operating (clicks are heard) and the relay / PEUP6 (the buzzer is buzzing)
Open circuit in the circuits of control or signal lamps of direction indicators:

- Broken threads of control or signal lamps

Check the reliability of the contact in the detachable connections. Check wiring harness integrity

Replace lamps

The door open buzzer does not work when the rear fog lights are on and the starter and instrument switch key is removed:

- Open circuit, short circuit

Check the fuse is good. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

- Faulty rear fog light switch

Check the function of the switch, replace if necessary

- Faulty limit switch

Check if it works, replace if necessary

- Faulty signaling relay

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

- The gap between the left door and the doorway in the area of ​​the limit switch installation has been increased

Adjust gap in doorway or adjust limit switch

Check the operation of the switch, replace if necessary

Wiper not working:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

- Faulty steering column switch

Check the operation of the switch, replace if necessary

- Faulty wiper relay

Check the operation of the breaker relay, if necessary, replace it

- Faulty wiper gear motor

Check the operation of the gearmotor, replace if necessary

Wiper motor is overloaded. When turned on, noise and rattle are heard, then it turns off (the thermal fuse has tripped):

- Rods are hooked on the cab parts

Ensure clearance between the rods and cab parts

- Traction jammed, brushes frozen

Ensure clearance between rods and cabin parts, eliminate freezing

Window washer not working:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

- Faulty steering column switch

Check the function of the switch, replace if necessary

- Faulty washer pump

Check pump performance, replace if necessary

Indicators do not work: fuel level, coolant temperature pressure, pressure in the pneumatic system*:

- Open circuit, short circuit. Faulty sensors

  • Check the reliability of the contact in the detachable connections.
  • Check the integrity of the wiring harness.
  • Check fuses F20, F9. If the fuses are defective, repair the short circuit in the circuit, replace the fuses.
  • Check the functionality of the sensors, replace if necessary
Tachometer not working:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse F20. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

  • - Faulty tachometer. Open circuit from the "~" terminal of the generator to the tachometer
  • - Faulty geneErator

Replace tachometer

Check circuit in harnesses from alternator to tachometer

The blinking mode of the brake indicator lamp does not work:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse. In the event of a fuse failure, eliminate the short circuit in the circuit, replace the fuse

- Faulty relay-breaker of the control lamp

Check the operation of the relay-breaker, in case of a malfunction, replace it

- Faulty parking brake sensor

Check that the sensor is working, if it is faulty, replace it

Heater motors do not work:

- Open circuit, short circuit

Check the reliability of the contact in the connections. Check the integrity of the wiring harness. Check fuse. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

- Faulty switch

Check that the switch is working, replace if it is faulty

- Faulty motor

Check the serviceability of the electric motor, in case of a malfunction, replace it

The warning lamps do not work: air pressure, emergency pressure clogging of the differential locks:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuses F20, F9. If the fuses are defective, repair the short circuit in the circuit, replace the fuses

- Malfunction of the corresponding sensors

Check that the sensors are in good working order, in case of a malfunction, replace them

- Destruction of the filament of the corresponding control lamp

Replace pilot lamp

Dehumidifier not working:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harnesses. Check fuse. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

- Faulty air dryer

Check the condition of the dryer, in case of a malfunction, replace it

The socket in the cab does not work:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuses. If the fuse is defective, repair the short in the circuit and replace the fuse

Radio does not work:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuses. If the fuses are faulty, eliminate the short circuit in the circuit, replace the fuse

- Faulty radio

Check if the radio is working.

Starter does not turn on:

Open circuit, short circuit. Faulty starter intermediate relay. Faulty starter and instrument switch. Faulty starter

  • Check the reliability of the contact in the detachable connections. Check wiring harness integrity
  • Check starter intermediate relay, replace if necessary
  • Check the operation of the starter switch and instruments, in case of a malfunction, replace it
When the mass is turned on, the voltage arrow remains in place:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse F1. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

When the engine is running, the generator set health indicator lamp is on:

- Faulty generator

Repair or replace the generator.

The ground switch does not turn on from the cab:

- Open circuit. Power button broken

Check the reliability of the contact in the detachable connections. Check wiring harness integrity

- Faulty short circuit switching relay

Check if the button is working, replace it if it's broken

- Burning battery switch contacts

Check that the relay is working, replace it if it is faulty. Strip switch contacts

Speedometer not working:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse. If the fuse is defective, repair the short circuit in the circuit, replace the fuse

- Faulty speedometer

Check that the speedometer is working, replace if it is broken

- Faulty sensor

Check that the sensor is working, if it is faulty, replace it

The backlight lamps - pointers and switches do not work:

- Open circuit, short circuit

Check the reliability of the contact in the detachable connections. Check the integrity of the wiring harness. Check fuse. If the fuse is defective, repair the short circuit, replace the fuse

- Faulty backlight rheostat

Check if the backlight rheostat is working

- Faulty switching relay for side lights

Check that the relay is working, replace if it is faulty