See Figures 1 and 2
The alternating current generator (alternator) supplies a continuous output of electrical energy at all engine speeds. The alternator generates electrical energy and recharges the battery by supplying it with electrical current. This unit consists of four main assemblies: two end-frame assemblies, a rotor assembly and a stator assembly. The rotor assembly is supported in the drive end-frame by a roller bearing. These bearings are lubricated during assembly and require no maintenance. There are six diodes in the end-frame assembly. These diodes are electrical check valves that also change the alternating current developed within the stator windings to a direct current (DC) at the output (BAT) terminal. Three of these diodes are negative and are mounted flush with the end-frame, while the other three are positive and are mounted into a strip called a heat sink. The positive diodes are easily identified as the ones within the small cavities or depressions.
The V6 engines experienced engineering changes to improve alternator performance. The alternator in these engines feature a high ampere output per pound of weight. It has an integral regulator but DOES NOT use a diode trio. The stator, rectifier bridge, and rotor with slip rings and brushes are electrically similar to other alternator models.
The regulator voltage varies with temperature and limits system voltage by controlling rotor field current. It switches rotor field current on and off at a fixed frequency of about 400 cycles per second. By varying the on-off time, correct average field current for proper system voltage control is obtained. At high speeds, the on-time may be 10 percent and the off-time may be 90 percent. At low speeds, with high electrical loads, the on-off time may be 90 percent and 10 percent respectively.
The V6 engine alternator is not serviceable. If the alternator is found to be defective, replacement is the only alternative. Even though the other alternators may be serviced, purchasing a new or rebuilt component is often easier and more time-effective.
To prevent damage to the on-board computer, alternator and regulator, the following precautionary measures must be taken when working with the electrical system.