Car alternator

There is a generator in each car. It serves to recharge accumulator battery and to supply the whole car with electric current. The engine drives in the result of firing. Generator, in its turn, is joined with engine and due to this electric currency is generated. The principle used here is known to everybody by the example of the cycle generator. Kinetic energy generated by the engine is transformed into the electric power. In modern cars alternating-current generator is used everywhere, but in old cars you can still meet direct-current generator.

If generator is faulty, accumulator battery is not supplied. It is a serious problem faced as a rule when you turn on ignition. In modern cars there is an indicator lamp that indicates generator faultiness, but it doesn’t mean to be a signal that the generator is completely broken down. As generator plays a very important role in vehicle operation, it is necessary to diagnose it as soon as possible. In the majority of cases generator can be repaired and there is no necessity in a complete change. Sometimes the cause of faultiness is a broken down diode or voltage regulator. Another cause may be a belt breakage, wire disconnection or bad contact.

Works with generator should be done with utmost care. A very high voltage can put generator out of action that is why similar works should be done by specialists. Automotive electrician will quickly find and correct the cause of the fault. If you need any other car parts for your car, visit our Internet shop. Here you will find break blocks, spark plugs, rear-view mirrors, horns, cylinders, and many other car parts.

Generator failures

• slip rings are soiled, burned or oiled;
• drive belt slips;
• excitation circuit is broken off;
• bearings are worn-out or damaged;
• nut of a pulley of the alternator is loosened;
• rotor contacts to stator poles;
• bracket seat is worn-out;
• periodical brushes jamming.

Signs of alternator failures

• battery is discharged or boils away;
• excessive noise when the unit starts working;
• light signal of a low charge battery is active at the started engine;
• dim headlights;
• quiet sounds and jingle are audible when engine operates;
• admissible car electric system voltage level is exceeded;
• headlights brightness changes sharply according to number of revolutions.

Causes of Generator failures

• use of low-quality components;
• worn out and oxidized alternator;
• malfunctions in a voltage control relay;
• clamping springs are damaged or deformed;
• incorrect operation of the part out of the normal mode;
• external influence of:
  • water;
  • high temperature;
  • salts;
  • chemical reagents on road surface;
  • dirt.

Diagnostics

The diagnostics of the unit should be carried out with the help of specialized devices, the ammeter and the voltmeter namely. It is possible to do it yourself or with help of service station specialists. Condition of the component is defined at diagnostic stands.

Search of the alternator failures should be started with measurement of voltage level on accumulator battery terminals. Then it is necessary to start the engine and take readings of devices once again. They should meet the following standards:

• before start — 12V;
• after start — 13,8–14,4V.

High figures are indicatives of failure of the voltage control relay, lower ones point to the lack of alternating current.

Repair and replacement of Generator

Usually the alternator service life is about 160 000 operational kilometers. It is often sufficient to replace faulty units or components to eliminate mechanical malfunctions. Some old alternators models may need turning of slip rings on a lathe. Drive belts replacement is performed at service life expiry, maximum tension or severe wear. At some service stations it is possible to carry out the part rewind, however it is expensive and inexpedient.