What are the analysis and diagnosis of common faults in tractor electrical system?

Analysis and diagnosis of common faults in tractor electrical system

In the use of tractors, due to the poor quality of electrical components, improper line connection, poor operating environment of tractors, resulting in water, gas invasion, resulting in electrical system failure is inevitable. It is of great significance to use the simple method to diagnose the fault quickly.

One lamp is a common fault.

1.1 The headlights are not on.

If you plug in the light switch on either baffle, neither headlight will work. Causes: one is the electric lamp before turning on or off the disconnect or rail; Second, the fuse is blown; Three is the lamp switch damage; Four is the lamp switch to the headlamp wire fracture.

Diagnostic instrument: open the headlight switch, the headlight is not bright, but the instrument is bright. Description The connection between the headlight switch and the headlight is loosened or disconnected; If the headlights and instrument lights are not on, then connect the rear light switch, if the rear light fuse is blown, it means that the headlight fuse is blown; If the rear light is off, it indicates that the power cable is faulty.

1.2 Burn light bulbs often.

The filament of its bulb often burns out during operation. The reasons are as follows: first, the voltage regulator is too high; Two is the regulator capacitor short circuit; Third, part of the charging line wire contact is bad, resulting in high no-load voltage of the generator. Diagnostic instrument: when the tractor is working, the ammeter shows that the charging current is very small, or it shows 0, and the filament burns off when the light is on. The charging line should be checked to determine poor contact. If the bulb has a short life and burns out frequently, check the voltage regulator to see if it is too large or the capacitor is short-circuited.

1.3 The headlight in front goes off and on.

The brightness of two headlights of a car differs greatly, and the inspection result is dark light and iron break. Why is the train not good or the train line broken, the lamp will shine as usual? The reason has: headlamp uses double silk lamp, cent far-light and near-light two kinds. One is mounted at the focal point of the reflector and emits a beam of far-light. The other is placed above the focal point, giving off a near light as the back of the mirror bounces below it. A lamp with a bad contact or a cut wire will not be cut off. When installing a high light switch, a lamp with a broken tie-in or tie-in wire will pass through another filament and two near-light lamps of the filament to form a channel. However, when the current passed through the filament, the resistance value increased and the brightness of the light decreased significantly, while the other lamp wire and the lap iron were normal. In this way, there will be a headlight dark a bright phenomenon. When in use, the power of the headlight or near light, the brightness of the two lights is slightly different is normal, this is because the length of the two lights is different, the joint and the iron situation is not the same, resulting in the size of the current through the two lights slightly different. Diagnostic: if a lamp is on the tractor, another lamp is obviously dark, which is caused by bad iron or broken iron line. The brightness of the two lamps is basically the same after eliminating the malfunctioning of the lapping or lapping wires.

1.4 Electromagnetic switch has poor absorbability.

Connect the ignition switch to the starting gear, the electromagnetic switch can not be tightly closed, making a sound of "da, da". Possible causes: (1) The battery is powered off or faulty. Poor contact between battery terminal and connecting wire. ③ The holding coil of the electromagnetic switch has an open fault.

Diagnostic: (1) Check whether the battery connection wire is loose and rusty. If it is loose, it should be tightened. If it is rusted, remove the connecting wire, wipe it clean with "00" sandpaper, and clamp it. Check whether the battery discharges. If there is serious power loss, charge or replace the battery. ③ If the battery is normal, check whether the electromagnetic switch hold coil is cut off. If something goes wrong, it should be replaced.

2 the automobile oil pressure representation value is not accurate.

The indicator value of fuel pressure gauge is not correct in the following two situations :(1) the oil pressure indicator is too high, indicating that there is a rail short circuit inside the oil pressure sensor. At this point, the ignition switch should be turned off immediately, otherwise the oil pressure will burn out. The wiring on the oil pressure sensor can be disassembled for inspection. At the same time, observe the ignition switch oil pressure gauge, so when, such as the needle does not move, the oil pressure sensor itself short circuit; If the pointer rises, it indicates a short circuit on the pressure gauge. (2) The oil pressure gauge is not indicated. When the oil pressure gauge is not displayed at startup, it indicates that the pressure gauge, sensor or lubrication system is faulty. Inspection method: remove the wiring of the oil pressure sensor and connect it with the shell. When the pointer of the oil pressure gauge moves around immediately, it proves that the dial works normally. It may be that the sensor is faulty. Still refers to zero, indicating that there is a fault in the table or lubrication system.

The third is whether the battery capacity is enough.

The diesel engine failed to ignite. Diagnostic: when the starter is connected, according to the voltage change, use 0~30V DC voltmeter or multimeter to measure the terminal voltage of the battery. Such as the use of 12V battery diesel engine, when starting, the battery terminal voltage can be maintained in more than 10V, indicating that the technical condition of the battery is good, after sufficient electricity, the terminal voltage is maintained in more than 9V, indicating that the battery partial discharge or slight vulcanization, after timely charging can continue to use. If the battery is lower than 9V but still cannot stay above 5 v, it indicates that the battery is fully discharged or may be faulty. If the voltage is lower than 9V and the voltage drops rapidly, it indicates that the battery is faulty. Charge and check the battery in time.

The starter does not rotate.

When the internal combustion engine starts, the electric starter stops working and the diesel engine cannot start. Diagnostic instrument: if the horn is sounded and the opening light is not on, the circuit is blocked, indicating that the battery wiring pile is in bad contact, or the battery has no power or lack of power. If the speaker is normal, it means that the battery and power supply line are normal. Short connect the two poles of the switch again using a guide wire or screwdriver. When the starting motor rotates, the starting switch is faulty: check the contact part of the starting switch to see whether the contact is clean and good; Whether the control lever, slip ring, one-way meshing device is stuck, or the coupling screw is improperly adjusted. For the electromagnetic switch starter, first turn off the starting switch and observe whether the electromagnetic start switch is closed. If not, it is necessary to further check whether the contact point and wiring of the starting switch are short-circuited. Electromagnetic switch to attract two auxiliary coils of the open or short circuit, can start from the starting switch, with spot welding method one by one detection. If the electromagnetic switch attracts and does not start, the fault occurs in the contact part of the electromagnetic switch. If the starter motor does not turn, the starter will have internal failure.