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JS Alternators 1UR 3UR 250 320+ amp Alternator 6 phase hairpin Toyota UR V8 Tundra Sequoia Land C...

JS Alternators 1UR 3UR 250 320+ amp Alternator 6 phase hairpin Toyota UR V8 Tundra Sequoia Land Cruiser LX570 LS460

Select your specific UR engine application from the dropdown menu!

For those that need more electricity than the stock alternator can provide, we have teamed up with JS Alternators to offer these custom made to order options! Even better, theyre plug and play, no adapter wiring needed!

JS Alternators also requires their universal Big 3 wiring kit, or otherwise similar wiring upgrades in addition to the factory wiring in order to handle the higher output. The big 3 Wiring upgrade is an ADDITION to your factory wiring.
All factory connections need to remain connected. For protection, it is recommended to add an in line fuse to the positive wire. All grounds must be cleaned to bare metal and properly secured.

Big 3 wires are 1/0 gauge pure copper cables. 1 positive to connect from the positive stud on the alternator to the positive battery terminal. Other 2 ground wires go from the alternator mount bolt to frame/chassis, and negative on the battery to frame/chassis.

Most JS Alternators are custom built to order and typically take 5-15 business days to be built and shipped. All JS alternators have a lifetime warranty on labor, and 1 year warranty on parts.

Hairpin units are commonly called 6 phase. They produce more output at idle and are more efficient than a conventional alternator. JS Alternators hairpin units feature premium bearings to withstand high engine rpm and utilize dual plate rectifier with 12 heavy duty diodes for improved cooling. Hairpin Units are a more reliable alternator to withstand high heat, high demand for car audio, marine, and racing applications.

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  • $359

REQUIRED Installation Steps: 

(Wear eye protection, remove jewelry/loose items, and allow car to fully cool before starting installation)

  • Batteries must be fully charged before installation.
  • Make sure vehicle is off and engine is cool.
  • Disconnect the negative cable from the battery/batteries.
  • Disconnect all other wiring from the alternator.
  • Remove the belt (note the belt routing before removing).
  • Remove the bracket bolts and original alternator.
  • Mount the new alternator. Typically the original bolts will be used.
  • The belt must be replaced with a .5 to 1-inch shorter belt when installing a high output alternator, unless otherwise specified.
  • Install the new belt. Make sure the routing is correct and the belt is aligned with all pulley grooves.


It is highly recommended you add a dash mounted volt gauge.

  • Connect the battery ground and confirm all other electrical connections are complete.
  • Confirm the belt path is correct and clear of obstacles.
  • Before starting the vehicle confirm that the battery is charged, as starting the vehicle with a discharged battery can damage the alternator.
  • Use a battery charger to charge the battery first if voltage is inadequate.

Ground Path Resistance Test

If resistance is greater than 0.1V confirm the following:

  • Confirm that all paint, anodizing, or rust is removed, and the connections are to bare metal.
  • Make certain all terminals are tight to the wire.
  • Make certain the ground wire is of proper size.

Charge Path Resistance Test

If resistance is greater than 0.1V confirm the following:

  • Make sure alternator charge post nut is tight.
  • Make sure charge wire is proper size.

Battery Recommendation

  • 2000 watts: upgrade main battery, 1 rear battery
  • 3500 watts: upgrade main battery, 1-2 rear batteries
  • 5000 watts: upgrade main battery, 2-3 rear batteries
  • 7500 watts: upgrade main battery, 3-4 rear batteries – 2 alternators
  • 10,000 watts: upgrade main battery, 3-5 rear batteries – 2 alternators
    • SKU
    • Weight
      10 lbs
  • Version
    250 amp, 320 amp, 370 amp, 400 amp
  • Engine/Wiring Fitment
    2007-2017 LS460, 2008-2011 LX570, 2008-2010 Land Cruiser 3UR, 2007-2014 Tundra 1UR/3UR, 2008-2012 Sequoia 3UR
  • Powdercoating
    No, Yes, contact for color options
  • Include Big 3 Wiring Universal Upgrade (Required)
    Yes, No

Most product ships from either the manufacture or largest wholesale location to pass the saving to you. Most orders will ship via UPS, as we will be able to provide the best rates and have had the least issues when using UPS.

IF YOU DO NOT LIKE THE AUTOMATED SHIPPING CALCULATOR'S RATES, PLEASE CONTACT US AND WE CAN GET YOU A BETTER ONE! Especially for anyone outside the USA, please contact us with a list of parts you'd like to order, and where you are located.

We accept the following payment methods:

Also Venmo and unmarked nonsequential dollar bills

  • Fitment Type
    Vehicle Specific
Toyota/LexusTundra2007-2021 2nd Gen3UR-FE 5.7 V8 3UR-FBE
Toyota/LexusTundra2007-2021 2nd Gen1UR-FE 4.6 V8
Toyota/LexusLand Cruiser200 series / Lexus LX570 (2007-2021)3UR-FE 5.7 V8

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