Isuzu DMAX RG 4JJ3 Upgraded Alternator Kit (BKS-240DMAX)
Built for Touring Loads
Designed to power dual batteries, fridges and 4WD accessories
Direct Bolt-In Upgrade
OE-style fitment for straightforward installation in compatible vehicles
240A REPLACES 130A
Close to double the factory output, so a loaded touring system is no longer sitting at capacity.
Heavy Duty Construction
Durable alternator design with efficient cooling for long-term reliability
High Load Charging Stability
Maintains strong charging output even under heavy electrical loads from modern accessories.
The BKS-240DMAX kit pairs a Black Series 240A alternator with an Elevate Automotive wiring harness cut specifically for the Isuzu D-MAX RG and its 4JJ3-TCX engine. The factory alternator is sized for a standard vehicle. Add a second battery, a fridge, driving lights, a compressor and a UHF and it spends most of its working life at capacity, which is when voltage starts to sag, the DC-DC charger backs off, and the auxiliary battery never quite gets to full.
This one puts out 240A cold and around 217A hot, through a 7PV fixed pulley on a 17mm shaft. It runs an internal LIN regulator, so it communicates with the vehicle the way the factory unit does rather than being an unmanaged high-output alternator dropped into a smart charging system. Mount spacing is 161mm centre to centre and the mount leg ID is 55mm, matching the factory location, so it goes in where the original came out.
The harness is the half people underestimate. Factory cabling was never sized to carry 240A, and leaving it in place is the most common reason an upgraded alternator does not deliver what it says on the box. The kit includes upgraded cable cut to suit the RG engine bay, with the lugs already labelled, plus a 250A mega fuse and holder on a stainless bracket, so the extra output actually reaches the battery rather than being lost as heat in undersized wire.
Check your engine before ordering. This kit is for the 4JJ3-TCX. If you have the earlier RC D-MAX with the 4JJ1 engine, we build the same kit for it:
Isuzu D-MAX RC 4JJ1 240A Upgraded Alternator Kit →
Identical kit and the same alternator. Only the fuse bracket and the cable lengths differ, to suit the 4JJ1 engine bay.
Worth being clear on one more point: an alternator is a charging source, not a charger. If you are running a lithium auxiliary battery you still need a DC-DC charger or a battery management system between the alternator and the lithium bank. This kit gives that charger far more to work with, but it does not replace it.
Backed by a 2 year or 25,000km manufacturer warranty.
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.
