power from the battery to start the engine. After the engine starts the alternator takes over and supplies most of the power needed when the engine is running.
It also recharges the partially depleted battery to maintain full cranking power for the next engine start. Today's electronic heavy cars and light trucks would quickly exhaust the power in the battery without it.
Some of the common causes of premature alternator failure include:
- Weak/Dead Battery. When the battery begins to wear out, the alternator must work harder to restore power. In many cases, a dead battery can not be fully recharged by the alternator. Weak and Dead batteries cause the alternator to overheat and the eventual result will be premature failure. If your battery runs down, recharge it with a suitable battery charger instead of relying on the alternator.
- Oil Soak- Alternators that are mounted low on the engine may be exposed to oil from leaking engine components. The oil works it's way into the alternator internal components and softens protective coatings on wires, brushes, and other electronic components. Repairing oil leaks when they first appear is the key to preventing this type of failure.
- Improperly Fitted Drive Belt- A drive belt that is to lose will cause vibrations through the alternator that, over time, cause damage. A drive belt that is to tight will put undue stress on the bearings in the alternator and lead to failure. Properly fitted drive belt systems prevent this type of damage.