Search by number: 2004 Ford Explorer 4.0L 6 Cyl Alternator ProAmp 8446 $126.00 each OPTIONS: Without black cover on back ProAmp 7787 $133.00 each OPTIONS: With black cover on back. ProAmp 7787HD220 $298.00 each OPTIONS: 220 Amp; Custom Built ProAmpN 8446N $182.00 each OPTIONS: Without black cover on back ProAmpN 7787N $182.00 each OPTIONS: With black cover on back. Why is there more than one unit for my car? Look at the TECH SPECS when more than one unit is shown for your car. AMPS (ELECTRIC CAPACITY): must match you vehicle electric requirements. *** Call us if you are looking to increase your unit capacity! OE ALTERNATOR MANUFACTURER: It is recommended to match the Make of your alternator