What are the precautions for replacing the generator in the car?

Precautions for disassembling and assembling generators.

Disassembly points. 1. Do a good job of assembly marking. Start by cleaning the generator casing, draw a few straight lines between the front and back covers of the generator, you can use chalk.

Marking so that we can know the alignment between the front cover and the back cover when assembling, so as to prevent misassembly.

2.How to remove the end cap. There are 3 screws on the front and rear end covers, and the direction should be upwards when removing the rear end cover, otherwise it is easy to tear off the joints on the armature winding, and the rear end cover should be gently knocked with a wooden rod, and the hammer should not be used to disassemble it with gravity.

Remove the 3 binding post nuts and take out the terminal head to get out the stator.

3.Remove the brush holder, then remove the pulley and front cover. Remove the magnetic field and negative terminal post from the rear end cover first, and remove the brush holder to put back the nut to prevent loss. When removing the component board, do not discard insulating gaskets and spring pads, etc.

Assembling points. 1.Pay attention to cleaning and adding grease.

Be sure to clean each component before installation, such as end caps and bearings that can be cleaned with gasoline, and components such as rotors and stators that can be brushed with a soft brush. Apply grease to the bearing cover, and the amount of addition has been coated with the pores 2 3 is better.

2. Pay attention to the installation of carbon brushes. First, put the carbon brush lead connector on the 2 screws of the matching, install the carbon brush holder on the rear end cover, pad the insulating pad and spring pad on the back cover, and then fix it with a nut. After installing the brushes, check the resistance value of the F terminal post and the shell, use one end of the multimeter terminal post, and the other end of the shell, the resistance value should be infinity (not on).

3. Pay attention to the installation of wiring harnesses. After installing the generator, the torque and fastening of all kinds of binding posts should be checked, otherwise it will be easy to ablate the +B binding posts and wiring harnesses.

The car generator is the main power source of the car, and its function is to supply power to all electrical equipment (except the starter) when the engine is running normally (above idle), and at the same time charge the battery. On the basis of the three-phase stator winding of the ordinary alternator, the number of winding turns is increased and the terminal is drawn out, and a set of three-phase bridge rectifier is added. At low speeds, it is output in series by the original winding and additional winding, and at higher speeds, it is only output by the original three-phase winding.

1. When the engine is above medium speed, the ammeter pointer indicates that it is not charging, and the charging indicator light is on, first of all, the battery charging situation should be considered, if the charging is insufficient, it is the fault of the power generation device.

2. In addition to the loose and slippery transmission belt, it is generally necessary to check that the generator itself does not generate electricity or the regulator is faulty, as well as the charging circuit is broken fault. For example, the internal rectification of the generator falls off or the contact between the bottom of the armature binding post and the diode component board is not connected; The diode breaks down and short-circuits, causing the stator winding to burn out; The brushes are stuck in the carbon brush holder, the contact is poor, or the magnetic field winding is broken, etc.

3. Improve the engine rotation in diagnosis; Turn on the headlights, such as the instantaneous deflection of the ammeter pointer to the direction of discharge, it means that the generator and regulator are working normally, but the battery is fully charged; If the pointer of the ammeter is large and deviates to the direction of discharge, the fault lies in the generator or regulator, and the connection of the charging line should be checked whether the connectors are good, whether the fan belt is too loose and the technical condition of the generator and regulator. First of all, verify whether the charging system is indeed faulty, put the engine to run at medium speed, and at the moment of turning on the headlamp, the ammeter pointer is biased in the "+" direction or remains in place, so that the battery is fully charged and the charging system is working normally. If the ammeter pointer is biased in the "one" direction, it means that the charging system is faulty and should be repaired.

First, pay attention to whether the selected model is the same as the original car. Second, whether the negative pole of the battery is disconnected during installation. Third, whether the battery fixing bolt is tightened according to the specified torque.

I don't know which Jetta you're talking about, but like you said, this should be the main door wiring harness is broken, that is, the wiring harness connecting the door and the body, peel off the skin to see the handle, there must be a short one, drag and drop one by one to see, the line of this car is the easiest.

Precautions for replacing the engine of the car, I personally think that it is definitely necessary to pay attention to the replacement of the engine of a car like this, and many places need to be changed if the engine is replaced like this. It should also be necessary to report.

Turn off the power of the battery, avoid abnormal ignition, pay attention to the disassembly and assembly sequence, and prepare special tools. When disassembling and assembling the accessory belt, first draw a coiling diagram for backup, the drive belt shall not be stained with oil and water, and the screws must be tightened according to the specified torque when installing the generator, and the final connection should be firm and reliable.

When disassembling the generator negative cable, the ignition switch should be in the "off" position. Prevent damage to the ECU and electrical equipment by the electromotive force generated by the grounding of the generator wire. 2) When disassembling the generator transmission belt, the hands of the staff should be clean, and it is strictly forbidden to stick grease and oil to the transmission belt.

3) The generator is very closely matched with the support frame. After removing the generator bolts, the motor can be loosened with a wooden crowbar, which makes it easier to remove the generator. 4) The tightening torque of the generator fixing bolt should meet the specified requirements.

Precautions during generator replacement; Before disassembling and assembling the generator, check and protect the vehicle, turn off the battery power, avoid abnormal ignition, pay attention to the disassembly and assembly sequence, prepare special tools and transmission belts, etc. When installing the generator, the screws must be tightened according to the specified torque, the connection must be firm and reliable, and the engine is the heart of the car. Whereas, an engine is a machine made up of many structures and systems.

It can be said to be very complicated. There will inevitably be times when repairs are needed. Different types of engines have different structures.

There are also different precautions when it comes to maintenance. Next, let's take a look at how to disassemble, repair, and install the engine. We're going to make cars to use.

Know the age of the car, mileage, damaged parts, fuel consumption, etc. And check if the appearance and accessories of the engine are complete? Such as cylinder block, cylinder head, water pump fuel system, etc.

Check for oil leakage or abnormal noise, and start the engine. Also check the cylinder compression pressure. Cylinder pressure affects engine power.

The degree of wear of the cylinder piston can be judged by inspection. Then it is necessary to determine the engine model so that it can be correctly matched with the tools used in the repair. Before disassembling the engine, remove the battery to avoid fire.

During disassembly, they should be discharged sequentially. For reinstallation. When removing the vacuum tube, the middle of the hose should not be pulled.

And pay attention to mark the connecting end of the hose. Avoid installation errors. The engine must be disassembled after cooling to prevent deformation due to excessive temperature during disassembly.

and use professional tools. Be sure to tighten the bolts when overhauling. The tightness of the pump fan housing should meet the technical requirements.

If it is too tight, it will not only break easily, but also shorten the service life of the belt.

In addition, excessive tension can cause deformation of the generator shaft and pump shaft. Generally, the normal belt device is 10-15 mm, and when installing the crankshaft and connecting rod shaft, sufficient lubrication must be maintained, otherwise the shaft will be stressed when the engine rotates.

When installing the bolts, first use a cleaning tool to ensure that the screw holes are clean and free of dirt or water. When installing valve springs, it should be noted that the direction of the springs can be pre-marked. If you forget about the usual situation, the place with high spring density is facing downward.

If the engine temperature is relatively high, never blindly disassemble the thermostat. The coolant does not regulate the cooling intensity. It is difficult to guarantee that the engine will work at the right temperature.

Moreover, the engine works at low temperatures, which will cause the engine power to decrease, fuel consumption to increase, and wear to accelerate. The correct way to do this is to check the rest of the cooling system. Instead of removing the thermostat.

The problem that needs to be paid attention to when replacing the car engine is that we must pay attention to the process of engine installation, and we must also pay attention to whether the installation of the engine is correct, and we must also pay attention to protect our body when installing the engine, and also pay attention to not rubbing the vehicle when installing, which are all problems that need to be paid attention to when installing the engine.

Pay attention to the brand of the engine, but also pay attention to the quality of the engine, but also pay attention to the method of replacement, at the same time pay attention to the installed parts, but also pay attention to the installation of the engine, and so on.

It is necessary to pay attention to the circuit before the disassembly, as well as the connection situation, such as some screw mouths must be screwed up, and pay attention to the way of connection to prevent it from being unusable after disassembly.

Hello! The structure of the alternator and the voltage regulator is simple, easy to maintain, and if used correctly, it not only has few failures but also has a long life; If it is not used properly, it will be damaged quickly. Therefore, the following points should be paid attention to in use and maintenance:

1) Correctly connect the positive and negative poles of the battery and the generator and connect the good world pillar, and cannot be reversed. Otherwise, the electronic components of the generator or regulator will be burned out.

2) The connection between the generator and the battery should be firm, if it is suddenly disconnected, it will produce a sudden increase in overvoltage, and damage the electronic components of the generator or regulator.

3) When the generator is running, it is not possible to check whether the generator generates electricity by the method of fire test, otherwise the rectifier diode will be damaged.

4) Once it is found that the alternator or regulator has a fault, it should be overhauled immediately and the fault should be eliminated in time, otherwise it will cause a greater fault or battery power loss, so that the car can not drive.

5) The voltage level of the alternator must be the same as the voltage level of the regulator, and the type of alternator must be the same as the type of the regulator, and the power of the regulator shall not be less than the power of the generator.

6) the line connection must be correct, the installation position and wiring mode of the regulator of various models are different at present, so special attention should be paid to the wiring.

7) The regulator must be controlled by the ignition switch, and when the generator stops rotating, the ignition switch should be disconnected, otherwise the magnetic field circuit of the generator will be turned on all the time, not only will burn out the magnetic field coil, but also will cause the battery to lose power.

8) When it is found that the generator or regulator is faulty and needs to be removed from the car for maintenance, first turn off the ignition switch and all electrical equipment, remove the battery negative cable line, and then disassemble the wire joint on the generator.

The precautions for replacing the engine of the car are as follows:

1, the replacement of the engine should first pay attention to the relevant procedures of the engine, whether there is a corresponding certificate, whether the packaging is complete, whether the wooden box of the packaging is clearly marked, in principle, the replacement of the engine is to the vehicle management for change, the engine number should be the new number, the general number is mainly due to the engine does not have a certificate or to avoid the cumbersome procedures of the change, but this is not allowed pants age, if the car inspection is found, will not be able to carry out the car inspection. After replacement, the engine wiring harness and pipes should be checked to see if they are messy, and the run-in standard can be done in accordance with the run-in standard of the new carport.

2. Under normal circumstances, the replacement of the engine needs to be carried out by the staff of the 4S shop to help you change the pure code of the new engine number chain on the driving license. When replacing the engine, be sure to check the certificate of conformity and, if possible, identify whether the engine is new. As for other compensation, you need to negotiate with the 4S store.

3. The "Measures of the People's Republic of China for the Registration of Motor Vehicles" stipulates that the engine of a motor vehicle cannot be changed at will. The engine that has not been replaced without regulations has not been strictly tested or is itself a scrapped machine, the safety performance is greatly reduced, and the potential safety hazards increase.

The engine can be said to be the heart of the car. And the engine is a machine consisting of many structures and systems. It can be said that it is very complicated.

There will inevitably be times when repairs are needed. Different types of engines are structurally different. There are also different precautions when it comes to repairs.

Next, let's take a look at how the engine should be disassembled, repaired, and installed.

Before repairing. First of all, you have to do the car usage. Find out the car's age, mileage, damaged parts, fuel consumption, and more.

And check the exterior of the engine, are the accessories complete? Such as cylinder block, cylinder head, water pump fuel system, etc. If there is oil leakage, abnormal noise and start the engine to check.

The cylinder compression pressure should also be checked. Cylinder pressure affects the dynamics of the engine. The degree of wear of the cylinder piston can be judged by inspection.

Then you have to determine the engine model in order to correctly match the tools used in the repair. Before disassembling the engine, the battery must be removed to avoid **. And when dismantling, it should be discharged in order.

so that it can be reinstalled. When disassembling the vacuum pipe, do not pull the middle part of the hose. And care should be taken to mark the connecting end of the hose.

Avoid installation errors.

Pay attention to these few things. 1.The engine must be disassembled after cooling to prevent deformation during disassembly due to high temperature.

And you have to use professional tools. Be sure to tighten the bolts when overhauling. The tightness of the fan skin of the water pump should meet the technical requirements.

If it is too tight, it will not only break easily, but also shorten the service life of the belt. And excessive tension will cause deformation of generator shaft and water pump shaft. Generally, the normal belt device is 10-15mm.

2.When installing the crankshaft and connecting rod shaft, it is necessary to maintain sufficient lubrication, otherwise it will cause strain on the shaft when the engine is turning. When installing bolts, use cleaning tools to ensure the cleanliness of the screw holes, and there must be no dirt, water, dust, etc.

When installing valve springs, it is important to note that the direction of the springs can be marked in advance. If you forget, it is usually the case that the spring density is high and the place is facing downward.

3.If the engine temperature is relatively high, do not blindly remove the thermostat. Coolant does not regulate the intensity of cooling.

It is difficult to ensure that the engine works at the right temperature. Moreover, the engine works at low temperatures, which will cause the power of the engine to decrease, fuel consumption to increase, and wear to speed up. The correct way to do this should be to inspect other parts of the cooling system.

Instead of disassembling the thermostat.

Hope it helps!