Alternator: Description and Operation
GENERATORDESCRIPTION
The generator is belt-driven by the engine using a serpentine-type drive belt. It is serviced only as a complete assembly. If the generator fails for any reason, the entire assembly must be replaced.
On certain engines, the decoupler pulley may be replaced separately.
OPERATION
As the energized rotor begins to rotate within the generator, the spinning magnetic field induces a current into the windings of the stator coil. Once the generator begins producing sufficient current, it also provides the current needed to energize the rotor.
The stator winding connections deliver the induced AC current to 3 positive and 3 negative diodes for rectification. From the diodes, rectified DC current is delivered to the vehicle electrical system through the generator battery terminal.
Although the generators appear the same externally, different generators with different output ratings are used on this vehicle. Be certain that the replacement generator has the same output rating and part number as the original unit. Refer to Specifications and see Generator Ratings for amperage ratings and part numbers.
Noise emitting from the generator may be caused by: worn, loose or defective bearings; a loose or defective drive pulley (decoupler pulley); incorrect, worn, damaged or misadjusted fan drive belt; loose mounting bolts; a misaligned drive pulley or a defective startor or diode.
An instrument panel mounted, battery charge indicator lamp is used. When the key is in the on position, the lamp will be illuminated. This is done as a bulb check. If this lamp remains illuminated while the engine is running, a Diagnostic Trouble Code (DTC) has been detected for the charging system.