High Output Alternator for Jeep Cherokee Comanche Wagoneer (1987-1990) 4.0L

High-Amp 250A Direct-Fit Alternator for 1987-1990 Jeep Cherokee, Comanche, Wagoneer (XJ/MJ)

What it Does: The 250-amp high output alternator replaces the low-output factory charging unit on 1987-1990 Jeep vehicles to eliminate voltage drops and support high-draw electrical accessories without taxing the battery.

The Stock Jeep Cherokee, Comanche, Wagoneer Charging Deficit

Factory charging systems on the XJ and MJ platforms rely on stock alternators rated between 66 and 85 amps. When running auxiliary equipment such as high-tonnage recovery winches, high-output off-road LED arrays, upgraded audio systems, or electric radiator fans, current draw exceeds stator capacity. This causes voltage sag down below 12.0 volts at curb idle, excessive diode heat soak, continuous deep-cycling of the starting battery, dimming headlights, and premature starter degradation on the AMC 242 4.0L inline-six engine.

The Engineering Solution

This 250-amp heavy-duty charging unit delivers solid amperage across both idle and open-throttle operation. Engineered with heavy-gauge pure copper stator windings, a high-temp dynamic balanced rotor, and low-friction sealed bearings, this unit mitigates heat build-up under sustained electrical load. It features an integrated internal voltage regulator set for a constant 13.5 to 14.5 volts and drops directly into the OEM engine brackets with matched rotation, correct pulley offset, and a factory-matched harness plug requiring no core charge or casing alterations.

What's Included

• 1 x 250 Amp High Output Alternator (Part # 7897)

Technical Specifications

Compatibility

• 1987-1990 Jeep Cherokee (XJ) 4.0L Inline-6
• 1987-1990 Jeep Comanche (MJ) 4.0L Inline-6
• 1987-1990 Jeep Wagoneer (XJ Chassis) 4.0L Inline-6

Frequently Asked Questions & Fitment Warnings

Does this fit the XJ and MJ Cherokee, Comanche, Wagoneer?

Yes, this is a direct bolt-on fit for 1987-1990 models equipped with the AMC 242 4.0L Renix inline-six engine; it does not fit 2.5L four-cylinder or 2.8L V6 engines.

Do I need to upgrade my vehicle wiring when running a 250-amp alternator?

While this alternator features a direct-fit plug, performing a Big 3 wiring upgrade (battery power, chassis ground, and engine block ground to 0-gauge or 4-gauge cables) is strongly recommended to safely carry the full 250-amp capacity without bottlenecking.

The Jeep Off-Road Standard

Engineered to handle sustained trail recovery operations, severe vibration, and extreme overland duty cycles, this high-output alternator delivers uncompromised reliability so your Jeep stays fully powered in rough backcountry terrain.