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Jeep LJ Cummins R2.8 Build - Electrical Documentation

Project Overview

This documentation covers the complete electrical system design for a 2006 Jeep LJ (Wrangler Unlimited) with a Cummins R2.8 Turbo Diesel engine swap. The build features a comprehensive electrical redesign including dual battery architecture, TIPM replacement, and extensive custom electronics.

System Architecture

The electrical system is organized into zones for logical distribution and maintenance:

Power Systems

Critical Systems

Lighting Systems

Control Interfaces

Stereo Systems

  • Audio Systems - Fusion head unit, JL Audio MV800/8i 8-channel amp, JL Audio speakers and subwoofers

Communications

Auxiliary Systems

Install Notes

Key Features

Dual Battery System

  • START battery: Driver rear wheel well - powers critical engine systems via PMU and SafetyHub
  • AUX battery: Passenger rear wheel well - powers accessories via inline CBs + Firewall CONSTANT bus (cabin distribution cluster)
  • Battery Isolation: RedArc BCDC Alpha 50 DC-DC charger with automatic jump-start assist

See Power Generation for complete battery and charging system details.

TIPM Replacement

Complete replacement of factory TIPM with modular power distribution:

Major Systems

  • Lighting Control: SwitchPros SP-1200 for offroad and auxiliary lighting
  • Command Touch CT4: Street-legal lighting and turn signal control
  • Audio System: JL Audio MV800/8i 8-channel amp w/ DSP, JL Audio marine speakers and 2× 8" subs with RGB LED
  • Communication: Rugged Radio G1 GMRS, STX 4-place intercom, WolfBox dash camera
  • Recovery & Air: Warn 10,000 lb winch, ARB air lockers, ARB Twin Air Compressor

Documentation Notes

Outstanding Items

Throughout this documentation, you'll find "Outstanding Items" checklists. These track design decisions, measurements, and tasks that need to be completed during installation.

View Global TBD Tracker - Centralized tracking of all To-Be-Determined items with priorities

Work in Progress

This is a living document that evolves as the build progresses. Some specifications may be marked as TBD (To Be Determined) and will be updated during the build process.

Outstanding Items

Live from open GitHub issues labeled tbd for this build. Full filterable view: TBD Tracker.

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Need a physical copy for the shop? Use the print page which combines all documentation into a single printable page optimized for 3-ring binder formatting (US Letter, duplex, with binding margins).

Open Print Page - All Jeep LJ docs on one page

To print or save as PDF:

  1. Click the Print Page link above
  2. Wait for the page to fully load
  3. Use your browser's print function (Ctrl+P / Cmd+P)
  4. Select "Save as PDF" or your printer
  5. For duplex printing, select "Print on both sides" with "Flip on long edge"