Black Series ALT 12V 240A, ISUZU D-MAX - 4JJ1, 4JJ3-TCX DSL [FIXED PULLEY]
CHARGES HARDER AT IDLE
Higher charge at lower RPM, holding a dual battery bank in a full state of charge.
FITS 4JJ1 AND 4JJ3-TCX
One alternator covers both D-MAX engines. Only the wiring harness is engine specific.
240A REPLACES 130A
Close to double the factory output, so a loaded touring system is no longer sitting at capacity.
DIRECT OE FITMENT
161mm mount spacing, M8 top mount and a 17mm shaft. Goes in where the original came out.
2 YEAR WARRANTY
2 years or 25,000km against defects in materials and workmanship, direct from the manufacturer.
The BKS-240DMAX is the Black Series 240A alternator for the Isuzu D-MAX, and it suits both the earlier 4JJ1 and the later 4JJ3-TCX. It replaces a standard 130A unit, so you are close to doubling the available current. It delivers 13.5V at 240A cold and 13.5V at 217A hot, and it makes that current available lower in the rev range, which is where a factory alternator struggles once a dual battery system, a fridge, driving lights and a compressor are all asking at once.
It is a direct OE fit in the factory location, with 161mm centre to centre mount spacing, a 55mm mount leg ID, an M8 top mount and a 17mm shaft. The pulley is a 7PV fixed type with 7 grooves. The regulator is internal with LIN communication, so the alternator talks to the vehicle the way the original did.
One compatibility check before you order: this unit is not compatible with L or M regulator alternators. If your vehicle runs one of those, this is not the right part.
Plan for the wiring. A battery positive wiring upgrade is required. Run 0 B&S cable from the alternator to the battery with a 250A mega fuse inline of the new B+ terminal. The factory cable was sized for a 130A alternator and will not carry this safely, and reusing it is the most common reason a high-output alternator never delivers what it is rated for. We build complete kits that pair this exact alternator with a harness cut for your engine bay:
Isuzu D-MAX RG 4JJ3 240A Upgraded Alternator Kit →
This alternator with the harness, fuse and holder for the RG 4JJ3-TCX.
Isuzu D-MAX RC 4JJ1 240A Upgraded Alternator Kit →
The same alternator with the harness cut for the earlier 4JJ1.
Worth knowing before you buy: this alternator must not be connected directly to a lithium battery, and doing so voids the warranty. A DC to DC charger goes between the alternator and any LiFePO4 bank. Wired that way it works exactly as intended and gives the charger far more current to draw on than the standard 130A unit ever could.
Quick Specs
Warranty
Connecting this alternator directly to a lithium battery voids the warranty. A DC to DC charger must be fitted between the alternator and any lithium bank.
