Alternators & Regulators: Description
The alternator used in the above vehicles consists of a rotor, stator, rectifiers, end shields and a drive pulley. An electronic voltage regulator is built into the interior of the alternator's rear housing. See Fig 1 .
The regulator, using integrated circuits, limits the output voltage generated by the alternator, by controlling the amount of current allowed to pass through the alternator field winding. It also regulates system voltage in response to changes in ambient temperature.
| Alternator Part No. | Volts | Rated Amp. Output |
|---|---|---|
| A4T25191 | 12 | 75 |
Rotation - Clockwise as viewed from drive pulley end.
Current Output - 17-25 amp. at 13.5 volts and 500 RPM; 63-70 amp. at 13.5 volts at 1000 RPM; and 74 amp. at 13.5 volts at 2000 RPM.
Brush Length - Standard 0.71 inch; Service limit 0.32 inch.
Brush Load - Standard, 0.7-1.0 lbs.; Service limit, 0.5 lbs.
Charging Voltage - 14.4 volts (±0.3 volts) at 68°F.
Temperature Compensation - Less 0.1 volt per 50°F.