In the article, we will consider the possible causes of a malfunction in the car's power supply system and troubleshooting methods.
To maintain the electrical wiring in good condition and prevent chafing and breakage of wires, it is necessary to clean the wires from dirt and dust and check the reliability of their fastening.
It is not recommended to disconnect plug connections unnecessarily in order to avoid loosening and breaking contacts.
Minor malfunctions in the electrical system can be corrected by the driver. Malfunctions of sealed and complex devices are eliminated by personnel admitted to these works.
To find a malfunction, you need to know the operation of the entire electrical system, its circuit and be able to understand electrical circuits both on the circuit and on the car.
Before finding a malfunction, you need to determine by external signs in which circuit it occurred.
Only after the circuit has been identified can troubleshooting begin.
When troubleshooting, they are usually guided by a diagram and follow a certain sequence, starting with checking the corresponding fuse.
When checking the group fuse, consumers powered through the fuse are turned on in turn.
To save time, it is recommended to look for a circuit malfunction including consumers operating in parallel.
During normal vehicle use, the battery is automatically recharged. If the batteries are gradually discharged or overcharged and the electrolyte begins to "boil", it is necessary to check the operation of the voltage regulator and the generator.
Generator
- Ammeter shows discharge current at normal engine speed
- Loose tension on alternator drive belts - Adjust belt tension
- Contact rings dirty - Wipe the rings with a cotton cloth moistened with clean gasoline. If contamination persists, clean with sandpaper and wipe again with a cloth
- Worn or stuck brushes in the brush holders - Check the height of the brushes, their free movement in the channels of the brush holder and the force of the springs; if necessary, replace the brush holder or brushes
- Rectifier failure - Replace rectifier
- Stator winding short circuit - Replace stator assembly
- Disturbance in the excitation circuit - Repair the circuit
- Worn or broken bearing parts - Replace alternator
- Generator fan deformed - Straighten bent spots
- Overheating of bearings
Belts too tight - Adjust belt tension
- Excessive wear of alternator brushes
Contact rings dirty - Wipe the rings with a cotton cloth moistened with clean gasoline. If necessary, clean with sandpaper and wipe again with a napkin
- Charging current too high
- Batteries discharged - Charge batteries
- Short circuit in the brush holder assembly or in the circuit between the generator and the regulator - Repair the circuit
- Faulty generator excitation disconnect relay - Replace relay
- Voltage regulator defective - Replace regulator
- Load current fluctuation
- If the fluctuation of the load current does not depend on the consumers of electricity, then the cause is the slippage of the drive belts - Adjust the tension of the belts
- Bad contact in the excitation circuit - Check the excitation circuits and the reliability of the connection in the places of transitional contacts
- Increased noise level during generator operation
- Loose pulley - Tighten nut
- There is no contact between the brushes and the commutator - Wipe the commutator with a clean cloth soaked in gasoline, or clean it. Clean the brushes or replace them with new ones.
- Check the condition of the brush springs and replace them if they are defective. Check if the brushes in the brush holders are jammed
- The starter does not work (the headlights do not dim when it is turned on)
- Short circuit or open circuit in the solenoid winding of the traction relay - Replace the traction relay
- Open or missing contact in the power circuit - Find the fault and repair the contact
- Brushes stuck in brush holders - Remove brush holder, remove brushes and remove brush dust
- Starter relay failure - Replace relay
- Open circuit in starter - Check and repair or replace starter
- The crankshaft of the engine does not turn with the starter (the traction relay is activated)
- Batteries discharged - Recharge batteries
- Oiled or dirty brush-collector assembly - Clean collector and brushes from oil, dirt, copper-graphite dust
- Poor contact between starter housing and vehicle ground - Ensure connection is secure
- Incorrect oil used in the engine - Change oil
- After starting the engine, the armature continues to rotate
- Faulty traction relay - Replace traction relay
- Starter relay contacts welded on - Replace relay
- Faulty starter inhibit relay - Same
- When the starter is turned on, the traction relay does not work (there is no characteristic click)
- Batteries discharged - Recharge batteries
- Open circuit of the solenoid winding of the traction relay - Replace the traction relay
- Instrument and starter switch failure - Replace switch
- Open or short in starter relay winding - Replace relay
- Starter armature rotates but does not turn crankshaft
- Fractured flywheel ring teeth or drive gear - Replace flywheel ring or drive gear
- Starter adjustment out of order - Adjust starter
- Drive failure - Replace drive
- When the starter is turned on, repeated clicks of the traction relay and blows of the gear wheel of the drive against the flywheel ring are heard
- Unreliable contact of the starter traction relay circuit - Check the contact connections and troubleshoot
- The holding winding of the traction relay is faulty - Replace the traction relay
- Faulty starter relay coil or contact - Replace relay
- When the starter is turned on, noise (grinding) of the drive gear is heard
- Starter mounted skewed - Set starter correctly
- The moment of closing the contacts of the traction relay is incorrectly adjusted - Adjust the gap between the gear wheel and the thrust washer at the moment the starter is turned on
- The drive gear does not systematically engage with the flywheel ring during normal relay operation
- Deburring the ends of the flywheel or drive gear teeth - File and deburr the flywheel or drive gear teeth
- Tooth ends of flywheel ring or drive gear worn - Replace flywheel ring or drive gear
Lighting system
- The lamp is off
- Filament broken - Replace lamp
- Open circuit, bimetal fuse tripped - Eliminate short circuit in the circuit, reset the fuses
- Missing contact in plug connections - Restore contact
- Switch failure - Repair or replace switch
- The lamp is dim
- Contact connections oxidized or dirty - Clean contacts or replace oxidized plugs
- The lamp bulbs are darkened due to the evaporation of the metal of the filament - Replace the lamp
- Batteries discharged - Charge batteries
- Excessive lamp voltage drop - Check for voltage drop. Eliminate causes of increased voltage drop
- The light in the lamp is flashing
- Periodic loss of contact - Restore contact
- Control and measuring devices. When the power supply is turned on, the arrow of the device does not change its position
- Fuse defective - Replace fuse
- Open circuit - Repair circuit
- Arrow deviation left from zero
- Wire breakage from pointer to oil pressure or coolant temperature sensors - Repair circuit
- The wires are incorrectly connected to terminals "B" and "D" of the oil pressure and coolant temperature indicators - Connect the wires in accordance with the diagram
- Short wire or fuel level sensor to vehicle ground - Repair short
- Deviation of the arrow to the right from the extreme mark
- Short circuit of the wire or there is no contact of the housing of the oil pressure or coolant temperature gauge with the vehicle ground - Eliminate the short circuit; restore contact
- Broken wire from the pointer to the fuel gauge sensor or there is no contact between the sensor and the vehicle ground - Repair the circuit; restore contact
- Wires are incorrectly connected to terminals "B" and "D" of the fuel gauge - Connect the wires in accordance with the diagram
- Sharp fluctuations of the arrow
- Periodical violation of contact of indicators and sensors with the mass of the car - Restore contact
- Contact broken in plug connections - Make sure plug connections are tight and clean
- N The high-speed and counting units of the speedometer do not work
- Contact connections in the power supply circuits are broken - Restore contact
- No earth on the receiver or contact with the instrument panel - Check and ensure contact with earth
- Suddenly, the speedometer and counting units of the speedometer stopped working
- Fuse blows - Find the reason that triggered the fuse. Troubleshoot
- Power wire broken - Troubleshoot
- The speedometer pointer fluctuates at a low speed, the arrow does not deviate
Phase wire break inside the pointer - Replace pointer
