Owners Nissan Almera new G15 body is often faced with the need to service the electric generator, especially if the car is equipped with an air conditioning system. The presence of a climate system complicates the drive circuit of attachments, making the dismantling procedure more labor-intensive compared to the basic versions.
Many car owners try to save on service costs and take on the work themselves. However, without knowledge of specific components, such as the belt tensioner and the location of the fasteners, you can damage fragile elements of the engine compartment or install the new unit incorrectly. In this article we will analyze each stage of removal, paying special attention to the nuances specifically for the version with air conditioning.
Preparing the workplace and necessary tools
Before you begin any manipulations, you must ensure access to the engine and prepare the tools. Working in a tight engine compartment requires care and the right keys. For Nissan Almera A G15 with an H4M (or similar K4M) engine will require a set of sockets and extensions.
You will definitely need a ratchet, a wrench and a set of 10, 12, 14 and 17 mm sockets. Pay special attention to the long extension cord, since the generator mounting bolts are often located in hard-to-reach places hidden behind other units. Don't forget the hex sockets for the belt tensioner.
- 🔧 Socket wrenches and sockets: 10, 12, 14, 17 mm
- 🔩 Extension for ratchet (minimum 200 mm)
- 🔑 Ratchet wrench
- 🔦 Powerful flashlight for illuminating hard-to-reach places
- 🧤 Gloves to protect hands from dirt and sharp edges
In addition to the tools, it is important to prepare a clean area for disassembly. It is better to immediately put the removed bolts and washers in a magnetic container or box so as not to lose them in the grass or asphalt. It is also recommended to have a rag on hand to remove dirt from the work area before unscrewing the fasteners.
⚠️ Attention: Before starting any work, be sure to disconnect the negative terminal of the battery. Even if you do not plan to remove the wires from the generator, accidentally shorting the key to ground can cause a short circuit and damage the engine ECU.
Dismantling protective elements and disconnecting electrical equipment
To access the generator on models with air conditioning, it is often necessary to remove plastic crankcase guards or lower mudguards. They are attached with plastic clips and bolts. Carefully prying up the clips, remove them so as not to break the fasteners. Remove the bottom protection if it blocks access to the pulleys from below.
The next step is to disconnect the electrical connectors. On the back of the generator there is a chip with a thick positive wire, protected by a plastic cap. Remove the cap, press the connector lock and carefully pull it out. Be careful not to damage the delicate contacts inside.
- 🔌 Disconnect the control connector (piece with thin wires)
- 🔋 Unscrew the nut securing the main positive wire
- 🛡️ Remove the protective plastic cap from the positive terminal
It is very important to check whether other wires are blocking access to the mounting bolts. Sometimes the A/C or power steering wiring can prevent the alternator from being pulled out freely. If this is the case, carefully move the harnesses to the side without bending them too much so as not to damage the integrity of the insulation.
Features of working with a belt drive and tensioner
This is the most critical stage when using air conditioning. Belt drive on Nissan Almera The G15 includes a generator, air conditioning compressor, pump and crankshaft pulley. The tensioner has an automatic mechanism that must be squeezed correctly to loosen the belt.
Use a suitable wrench or socket on the tensioner square rod (usually 14 or 17mm). Apply force in the direction indicated by the arrow on the tensioner body and lock it in a compressed state. Only after this can you remove the belt from the generator pulley.
If the belt is worn out, it is recommended to replace it together with the generator. The old belt may have cracks or abrasions, which will not allow the new generator to work properly and will quickly damage the bearings. Also inspect the bypass roller, if your configuration has one.
- Socket wrenches
- adjustable wrench
- Torque wrench
- Ratchet heads
The process of unscrewing the generator mounting bolts
After removing the belt, you can proceed to fastening the unit itself. On Nissan Almera G15 usually uses two mounting bolts: upper and lower. The bottom bolt is often long and goes through the bracket; unscrewing it can require considerable effort due to sticking.
The top bolt is usually accessible from the top, but may be covered by part of the throttle body or pipes. The bottom bolt is located at the bottom, and to unscrew it you will need to crawl underneath the car, having first removed the protection. Use an extension and a wrench to create leverage, but be careful not to strip the threads.
- 🔩 Loosen the top mounting bolt (usually 14 mm)
- 🔧 Unscrew the bottom bolt (17mm is often required)
- ⚙️ Remove the adjusting sleeve if it remains on the bolt
Sometimes the bolts can become stuck. In this case, you should not use excessive force right away. Treat the joint with a penetrating lubricant (such as WD-40 or similar) and let it sit for 10-15 minutes. If the bolt does not budge, try tightening it slightly and then loosening it to break up the corrosion layer.
☑️ Preparing to remove the generator
Removing the generator from the engine compartment
When all the bolts are unscrewed and the belt is removed, the generator is free. However, removing it can be difficult due to the tight layout of the engine compartment with air conditioning. The unit has significant weight and dimensions.
Gently rock the generator to free it from its seats. Try removing it from the top first. If this fails, you may need to remove additional pipes or brackets that are obstructing the outlet. Do not try to pull it out by force, so as not to damage adjacent hoses and wires.
⚠️ Attention: When removing the generator, pay attention to the position of the pulley. Make sure that it does not touch the cooling system or air conditioning pipes, as plastic becomes brittle at low temperatures and can crack.
After removal, inspect the seat on the cylinder block. Clean it of dirt and rust so that the new generator will fit tightly. This will ensure reliable ground contact and correct belt tension in the future.
Specifications and tightening table
When installing a new or remanufactured generator, it is extremely important to ensure proper bolt torques. Insufficient tightening will lead to vibrations and destruction of the bearings, and excessive tightening will cause the threads in the aluminum block to break.
Below is a table with recommended torque values for the main mountings on the H4M engine, which is installed on most versions Nissan Almera G15.
| Fastening element | Bolt size | Tightening torque (Nm) | Note |
|---|---|---|---|
| Alternator top bolt | M10 | 40-50 | Mounting to bracket |
| Generator lower bolt | M12 | 60-70 | Goes through the block |
| Positive wire nut | M8 | 10-15 | Don't overtighten |
| Belt tensioner bolt | M10 | 45-55 | After installing the belt |
To achieve accurate values, use a torque wrench. If such a tool is not available, tighten the bolts with moderate force, but be sure to check their security after the first ride. The lower bolt of the generator on the Nissan Almera G15 has a special length and thread, so replacing it with a bolt from another model is strictly prohibited.
What to do if the belt whistles after replacing the generator?
Most often this is due to improper installation of the tensioner. Make sure that the mark on the tensioner matches the position after installing the belt. Also check the condition of the generator pulley - if it is loose, a whistle will be inevitable.
New generator installation and final check
The installation process is a mirror image of dismantling, but requires more care. Reinstall the generator after lubricating the bolt threads with graphite grease or copper paste to prevent sticking in the future.
Before putting on the belt, make sure that all pulleys are lined up in the same plane. Loosen the tensioner, place the belt on all pulleys except the generator, and then on the generator pulley. Smoothly release the tensioner so that the belt takes its place. Check that the belt is not twisted and is completely seated in the pulley grooves.
- 🔄 Check the alignment of the marks on the pulleys
- 🔩 Tighten the mounting bolts to the correct torque
- ⚡ Connect the electrical connectors and the positive terminal
- 🔋 Connect the negative terminal of the battery
After assembly, start the engine and let it idle. Listen to the operation of the generator - there should be no extraneous noise, hum or squeak. Check the voltage at the battery terminals with a multimeter; it should be in the range of 13.8–14.4 V.
Before final assembly of the engine protection, check the operation of the air conditioner. Turn it on to maximum and make sure that the belt does not slip under load and that the generator does not make unnecessary sounds.
Correct belt tension and compliance with bolt tightening torques are the key to long service life of the generator and the entire power supply system of the Nissan Almera G15.
FAQ: Frequently asked questions when replacing a generator
In this section we will answer the most popular questions that owners have Nissan Almera when replacing the generator yourself. If you are faced with a non-standard situation, the answer may already be here.
Do I need to completely remove the battery when replacing the alternator?
It is not necessary to completely remove the battery, but it is highly recommended to disconnect its negative terminal. This will eliminate the risk of a short circuit when working with the positive wire of the generator. If possible, it is better to remove the battery for easier access to the bottom of the engine.
Is it possible to change the alternator without removing the air conditioning belt?
No, on the G15 model with air conditioning, the belt is a single drive for all attachments. To remove the alternator, the belt must be loosened and removed from all pulleys, including the air conditioning compressor.
What to do if the tensioner bolt does not turn?
If the tensioner is stuck, do not use excessive force. Try treating the mechanism with penetrating liquid. In rare cases, it may be necessary to replace the tensioner itself, since it is a consumable item and wears out over time.
How to check the functionality of an old generator before replacing it?
To check, use a multimeter in DC voltage measurement mode. Measure the voltage at the battery terminals with the engine running. If it is below 13.5 V or above 14.8 V, the generator is faulty. You can also check the diode bridge and windings on the stand.
Is it necessary to do a wheel alignment after removing the generator?
No, removing the alternator does not affect wheel alignment. Wheel alignment is only required after work on the suspension or steering. However, after replacing the belt, it is recommended to check its tension after 500-1000 km.