Information - Generator

The car generator is a mechanism that converts mechanical energy from the engine into electrical one. The generator is used to recharge the car battery. A good automobile generator must meet relatively high reliability requirements, since it ensures constant and proper function of many components of a modern car. The generator must also be resistant, lightweight and small sized and have a low noise level. To generate electricity, voltage must be submitted to the coil. This happens when you turn on the ignition switch. The amperage in the coil is coordinated by the voltage regulator. The generator rotor is driven by a V-belt through a pulley. The electromagnetic field, produced by an induction coil, induces alternating electrical amperage in the starter winding.

The voltage from the stator is rectified by the rectifying unit and made permanent. The rectified voltage goes then into the car`s on-board electric system. The generator operates in very unfavorable conditions. It is exposed to moisture, dirt, oil, which are even more harmful because of the high temperatures in the engine compartment. Even a short-term function of the generator disconnected from the battery should be avoided. The flash voltage that occurs when you disconnect the battery is very dangerous for all electronic systems and devices of your car. Nor can we allow the working capacity check of the generator on the "spark" through a short-time combination of pin terminals with the "mass" of the vehicle. In this case very high amperage goes through the rectifier unit, which will damage the power diodes.

Only a reliable and high quality electric generator can protect your vehicle from unexpected malfunctions and ensure the stable functioning of your vehicle. So if you want to buy a generator, go to our online store. And we guarantee not only lower prices, but also short delivery times. You can also order other car parts such as rear lights, fuel tank or springs.

What is necessary to know about automotive alternator replacement: lifetime limits, common defects and their signs, tips and recommendations

Lifetime limit of the car alternator is about 160 000 operational kilometres.

This component can lose operability due to destruction of the pulley, thermal damage of the brushes or contact rings, breakdown of the voltage regulator, short circuit of the stator winding, destruction of the bearing, damaging of the diode bridge and wires.

Common signs that indicate necessity of component diagnostics are excessive or insufficient voltage in the car mains. The first can be detected by quick breakdown of electric equipment, the second can be signalised by a special dashboard indicator. Also, alternator defect can be indicated by battery overcharge, coming with electrolyte boiling, or its quick discharge, which is noticeable due to activation of a special dashboard indicator. Moreover, unusual sounds during engine operation, dim headlights, changing of their intensity at rpm increase are also causes for alternator inspection check.

Diagnostics of the automotive alternator defects is performed at a service station and consists of measuring voltage in the car mains or checking demounted component with the help of a special stand. Voltage measuring is performed at the battery terminals, then the engine starts and readings are checked with the engine  running. Deviation of the readings from allowable values indicates the necessity of alternator replacement.

Replacement of the alternator is performed in car service station conditions. This procedure requires usage of special tools and includes works with high-voltage wiring and demounting of corresponding components. Particularly, you will need to remove the engine guard, a wiring harness connector,  belt and alternator adjustment bracket. After this, demount the alternator and install a new one.

Advices for our customers

How to maintain an alternator in an operative condition?

To maintain an alternator in an operative condition for a long time, it is necessary to perform its timely cleaning and replace worn out elements.

The maintenance work consists in regular checks of belt-tension and fastenings security, cleaning of the unit from dirt, bearings lubrication.

They should be performed with specified periodicity, which is usually noted by the vehicle manufacturer.

It is recommended to perform more thorough diagnostics every 24 000 operational kilometers. An alternator should be demounted, disassembled and cleaned. Learn from tutorial videos how to make it on your own. Alternators in diesel cars require more attention, than components installed in cars with petrol engines. They are combined with a vacuum pump, which also can break down.

How to check an alternator?

An alternator can be checked with the help of multimeter, without demounting it from the vehicle. To do so, you need to connect the device to corresponding terminals of a battery and perform the next actions:

  1. Check battery voltage at shut off engine. It should be about 12.5–12.7V."
  2. Start the engine, without turning on auxiliary units. Voltage of 13.8–14.5V range indicated alternator operability; and in some modern vehicles – 14.8V. If during rpm increasing it goes higher than noted value, most likely cause of the defect is in a regulating relay. At the breakdown of the latter, battery charge may not be performed at all.
  3. Measure the voltage on battery terminals at the maximum load of an alternator, particularly, with headlights, heater, windshield heating and others being turned on. It should be 13.7–14.0V. More detailed diagnostics is possible only with demounted alternator. Watch tutorial videos to know how to perform its demounting by yourself.

How to repair or replace an alternator?

To repair or replace an alternator you need to perform its dismantling. Actions sequence at the unit demounting may be significantly different according to the car brand and model. Use vehicle manufacturer recommendations to get more detailed instructions.

Repair works, which can be performed by your own, usually consist in replacement of brushes, clutch, alternator slip rings, bearings or diode bridge. More serious defects such as winding burn-out, shaft jamming or housing deformation require interference of specialists or whole assembly replacement. Installation of new tension rollers or belts is performed without component demounting.

Alternator at low cost: Top Spares

Alternator (LUCAS ELECTRICAL, LRA02235) -19%
Alternator | LUCAS ELECTRICAL LRA02235 Article №: LRA02235
LUCAS ELECTRICAL Alternator LRA02235
£ 153,49
£ 124,33
incl. 20% VAT, Shipping
Over 100 items in stock
  • Alternator Charge Current [A] 180
  • Voltage [V] 14
  • Belt Pulley Ø [mm] 62
  • Pulleys with freewheel belt pulley
  • Plug Type ID L-DFM (Plug 121)
  • Vehicle Main Current for vehicles with 12V main current
  • Clamp M8 B+
  • Bore Ø 1 [mm] 8
  • Thickness 1 [mm] 14
  • Length 3 [mm] 61
  • Number of Teeth 1 18T
  • Net weight [kg] 7,7
  • Condition  Remanufactured
Details
Alternator with integrated regulator (VALEO, 746124) -19%
Alternator | VALEO 746124 Article №: 746124
VALEO Alternator 746124
£ 142,49
£ 115,42
incl. 20% VAT, Shipping
Over 100 items in stock
  • Product line REMANUFACTURED CLASSIC
  • Alternator Charge Current [A] 120
  • Voltage [V] 14
  • Belt Pulley Ø [mm] 51
  • Pulleys with belt pulley
  • Number of ribs 6
  • Service exchange part
  • Supplementary Article/Supplementary Info with integrated regulator
  • Position / Degree L 35
  • Rotation Direction Clockwise rotation
  • Connector / Clamp without connection for speed sensor
  • Fastening Type Double Pivot Lever
  • Weight [kg] 6,75
  • Condition  Remanufactured
Details
Alternator Manual Transmission (AS-PL, A5166) -19%
Alternator | AS-PL A5166 Article №: A5166
AS-PL Alternator A5166
£ 128,99
£ 104,48
incl. 20% VAT, Shipping
Over 100 items in stock
  • Alternator Charge Current [A] 70
  • Voltage [V] 12
  • Length 3 [mm] 82,50
  • Length [mm] 43,00, 15,00
  • Condition  New
Details
Alternator with integrated regulator, REMANUFACTURED CLASSIC (VALEO, 746025) -19%
Alternator | VALEO 746025 Article №: 746025
VALEO Alternator 746025
£ 124,99
£ 101,24
incl. 20% VAT, Shipping
Over 100 items in stock
  • Supplementary Info REMANUFACTURED CLASSIC
  • Alternator Charge Current [A] 120
  • Voltage [V] 14
  • Belt Pulley Ø [mm] 57,2
  • Pulleys with belt pulley
  • Number of ribs 6
  • Service exchange part
  • Supplementary Article/Supplementary Info with integrated regulator
  • Position / Degree R 90
  • Rotation Direction Clockwise rotation
  • Connector / Clamp without connection for speed sensor
  • Fastening Type Double Pivot Lever
  • Weight [kg] 6,944
  • Condition  Remanufactured
Details
Alternator Sequential Manual Transmission (AS-PL, A2003PR) -19%
Alternator | AS-PL A2003PR Article №: A2003PR
AS-PL Alternator A2003PR
£ 111,99
£ 90,71
incl. 20% VAT, Shipping
Over 100 items in stock
  • Alternator Charge Current [A] 100
  • Voltage [V] 12
  • Length 3 [mm] 66,00
  • Length [mm] 35,50, 13,00
  • Condition  Remanufactured
Details
Alternator with integrated regulator (VALEO, 746020) -19%
Alternator | VALEO 746020 Article №: 746020
VALEO Alternator 746020
£ 118,49
£ 95,98
incl. 20% VAT, Shipping
Over 100 items in stock
  • Product line REMANUFACTURED CLASSIC
  • Alternator Charge Current [A] 90
  • Voltage [V] 14
  • Belt Pulley Ø [mm] 57,2
  • Pulleys with belt pulley
  • Number of ribs 6
  • Service exchange part
  • Supplementary Article/Supplementary Info with integrated regulator
  • Position / Degree R 90
  • Rotation Direction Clockwise rotation
  • Connector / Clamp without connection for speed sensor
  • Fastening Type Four-point mounting
  • Weight [kg] 6,05
  • Condition  Remanufactured
Details
Alternator (DENSO, DAN936) -19%
Alternator | DENSO DAN936 Article №: DAN936
DENSO Alternator DAN936
£ 181,99
£ 147,41
incl. 20% VAT, Shipping
Over 100 items in stock
  • Alternator Charge Current [A] 150
  • Rated Voltage [V] 14
  • Belt Pulley Ø [mm] 61,5
  • Pulleys with freewheel belt pulley
  • Number of ribs 5
  • Vehicle Main Current for vehicles with 12V main current
  • New Part
  • Condition  New
Details
Alternator (AS-PL, A4043) -19%
Alternator | AS-PL A4043 Article №: A4043
AS-PL Alternator A4043
£ 90,49
£ 73,30
incl. 20% VAT, Shipping
Over 100 items in stock
  • Alternator Charge Current [A] 100
  • Voltage [V] 12
  • Length 3 [mm] 54,50
  • Length [mm] 17,00
  • Condition  New
Details
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