During the maintenance of electrical equipment, they check the condition of fuses and thermal fuses, electrical wiring, connecting blocks of the mass switch, speedometer drive, front and rear lights, switch for the center differential lock warning lamp
Check the electrical circuit of the oil filter clogging lamp switch by shorting the switch output to ground, and the control lamp on the instrument panel should light up. Adjust the direction of the light flux of the headlights using the screen.
During the operation of batteries, it is necessary to periodically clean the batteries, clamps and wire lugs from dust and dirt.
To do this, the surfaces of the batteries must be wiped with a clean rag soaked in soda or a 10% aqueous solution of ammonia. In addition, it is necessary to check the fastening of the batteries in the box, the tightness of the fastening of the battery clamps to the wire lugs, clean the ventilation holes and check the electrolyte level.
Only distilled water should be added to batteries
In the cold season, in order to avoid freezing, water must be poured into the batteries immediately before starting the engine, since when recharging the batteries, the water will mix with the electrolyte more quickly.
Do not add electrolyte or acid to a battery unless it is known for certain that the low electrolyte level is due to electrolyte leakage. In this case, the density of the added electrolyte must be the same as that of the electrolyte in the battery. Once a year, in the fall, the generator and starter are removed from the engine for testing at the stand.
On the G273V generator set with a built-in voltage regulator, the seasonal adjustment screw is set to the position corresponding to the upcoming season: "L" - summer, "3" - winter.
When the screw is set to the "3" position, the voltage maintained by the regulator is 1.5 ... 3.0 V higher than in the "L" position, which is necessary to improve the charging of the batteries with an increase in their internal resistance in cold season.
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.
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 diagram and be able to understand electrical circuits both on the diagram 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 the 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.
When a bimetallic short-circuit fuse is triggered, disconnect the consumer circuit protected by this fuse, find and eliminate the fault that caused the short circuit, and then turn on the PR310 type fuse by pressing the button until it clicks.
It is forbidden to forcibly hold the button in the on position. The fuse type 13.3722 switches on automatically after the bimetal plate has cooled down.
If, after starting the engine when it is running at an average crankshaft speed with good batteries and disconnected consumers, there is no generator charging current, then check the health of the 60 A fuse, then check and, if necessary, adjust the tension of the generator drive belts.
A correctly tensioned belt, when pressed on the middle of the largest branch with a force of 40 N, should have a deflection of 15...22 mm.
The cause of failures in the operation of the generator set may also be a violation of the electrical contact in the circuits of the power supply system.
Therefore, first of all, you should make sure that the electrical contact of the wires is reliable at the generator terminals, in the connecting blocks between the wire bundles and in and correctness of the relay for turning off the excitation winding of the generator; using a test lamp, check for voltage at the terminal "B" of the generator.
The location of a broken circuit can be determined by shunting them by connecting an additional wire with one end to the “+” terminal of a non-working consumer, and with the other end to the circuit connectors, moving towards the current sources; the faulty section is the section parallel to which the additional wire is connected, if the consumer starts working at the same time.
If the consumer does not work when shunting the entire section of the circuit, check the reliability of its connection to ground.
A short circuit to ground is possible at the places where the wires are fastened with staples, at sharp metal edges, at bare wire lugs.
When the fuse blows the location of the short circuit is determined in the circuit from the fuse to the consumer.
When the wires are broken, they are connected by twisting and then soldering the cores of the wires, or replacing them with new ones of the appropriate sections and lengths; then insulate the wires with insulating tubes or insulating tape.
One of the malfunctions of the starter is the "backlash" of the gear teeth of the freewheel drive. This is mainly due to improper regulation of the moment of closing the contacts of the starter traction relay. In this case, the starter turns on before the gear engages with the flywheel ring.
Another malfunction is the burning of the contact disk of the traction relay.
The reason for the intensive burning of the contacts may be the unstable operation of the traction relay, when, when the starter is turned on, its repeated clicks are heard due to low batteries, a break in the holding winding of the traction relay, or burning of the contacts of the switching relay.
If, when you try to start the engine, you don’t hear a characteristic click of the starter relay, then the malfunction must be sought in the control circuit of the start-up system: ammeter - instrument switch and starter (terminals "AM" and "CT") - starter relay - starter interlock relay.
The starter interlock relay can be checked for proper operation by shorting to ground the brown wire coming from the starter relay terminal “K” to the interlock relay, having previously disconnected it from the latter.
Activation of the starter relay when the lock key is in the second non-fixed position indicates a malfunction of the starter interlock relay.
If the direction indicator and hazard warning circuits fail, first of all, the fuses and switches are checked, applying voltage to the devices bypassing the switching equipment.
To check the alarm switch, set the instrument and starter switch key to the first fixed position and connect the “+” terminals of the batteries and the “+” of the turn relay, then turn on the turn indicators with the combined switch.
If the direction indicators work, then the hazard warning light switch is faulty.
The operation of instruments (oil pressure gauges, coolant temperature and fuel level gauges) is based on the principle of a ratiometer.
Changing the resistance of the sensor depending on the value of the controlled parameter determines the strength of the current flowing through the windings of the pointer, which, in turn, affects the deviation of the arrow on the instrument scale.
Failures that occur in devices of this type are mainly caused by either a sensor failure or a broken contact in the sensor-pointer circuit.
If the arrow of the temperature or pressure gauge deviates to the left beyond the scale, and in the fuel gauge it goes off scale to the right, then this indicates a break in the wire connecting the sensor and the gauge, or that the terminals "B" and "D" on the pointer.
As a result of a short circuit in the sensor-pointer circuit, the arrow of the coolant temperature and oil pressure gauge may go off scale to the right, and the fuel gauge to the left.
Fault is determined by the deviation of the instrument pointer. If, when the wire is disconnected from the sensor, the arrow of the device does not change its position, then this indicates a short circuit in the circuit.
Let's note one feature of the tachometer, which can be erroneously recognized as a malfunction. It is connected with the fluctuations of the arrow when the consumers of electricity are turned off.
When you turn on the headlights or other consumers, the readings of the device are normalized.
This is explained by the periodic disconnection of the excitation winding of the generator when the batteries do not require recharging. At the same time, the pulses of the generator phase do not enter the input of the tachometer pointer.