JsAlternators High Output Alternator Installation Instructions

Last updated: May 2026

This page contains JS Alternators high output alternator installation instructions. For the complete step-by-step installation guide including tools list, belt installation, and post-install verification, see our comprehensive guide: How to Install a High Output Alternator: Step-by-Step Guide

Installation Overview

  1. Disconnect negative battery terminal
  2. Remove serpentine belt using belt tool on tensioner
  3. Disconnect alternator wiring harness and B+ cable
  4. Remove mounting bolts and pull alternator
  5. Install JS Alternators high output unit, torque all bolts to spec
  6. Reconnect all wiring
  7. Install new shorter belt (spec included with your order)
  8. Complete Big 3 wiring upgrade before reconnecting battery
  9. Reconnect battery, start vehicle, verify 13.5-14.8V charging

Important: The Big 3 wiring upgrade is required for all high output alternators. Factory wiring was not designed for 250A+ current. Big 3 Wiring Upgrade: Complete Guide

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