Diagnosis & Testing
The alternator provides power consuming components with current while the engine is running and maintains battery charge. The alternator is mounted on the front edge of the engine. The output of the alternator depends on engine speed. When the engine is idling, the alternator operates at approximately half of its maximum output. When the engine is idling with many power consuming components engaged, the alternator may be unable to maintain full battery charge.
The alternator creates an alternating current which is converted to a direct current in the rectifier bridge. The alternator also utilizes a built-in voltage regulator.
- Check that the wiring is in good condition.
Check for any abnormal noise from the alternator while the engine is running. Noise emitting from the alternator may be caused by:
Worn, loose or defective bearings
- Check the accessory drive belt for wear or slipping.
With the engine running at 2,500 RPM, headlights on and fan blower on high:
- The alternator output voltage should be 14.0 volts plus or minus 0.5 volts at 68°F.
- The alternator test amperage should be 135 Amps.
Removal & Installation
Remove or disconnect the following:
Install or connect the following: