New Fuse and Relay Center for all Duramax Harnesses shipping after January 1, 2017.  

Gen 4 LS will use the same fuse block plus an additional (2) relays for fans.

Fuse and Relay Center for Gen 5 LT Harnesses shipping after Jan 1, 2017.

Leave it to us

Doing it yourself sometimes doesn’t pan out. The typical LS, Gen 5 LT1 or Duramax harness has hundreds of individual wires and each has a specific place in the harness.  While setting it up for standalone yourself is possible with the right tools and information, you will also need to bring plenty of patience. Rely on our knowledge and experience instead to provide you with a harness that requires just 4 connections to make your LS, Gen V LT1 or Duramax Swap Engine run. Take a look at the LS Engine Gen 5 and Duramax pages for more details and examples of our work.

A Lauraland, LLC Enterprise​ 

Modify any Duramax, Gen 5 LT1 or Gen 4 LS Engine Wire Harness for use in your swap project.


  • Every harness is completely opened and electrically load tested.

  • Current Duramax Lead Time is 3 Weeks, Gen 5 LT is 3 weeks, Gen 4 LS is 5 weeks.

  • Simple 4 wire hook up to make the engine run. (A Single Ground, 12V Constant, 12V Key On, Fuel Pump)

  • Fuse Block included.  Relays for ECM/TCM and Fuel Pump (LS LT only) are included.
  • 6' OBD diagnostic port is included on every harness.

  • Contact us for a quote on LB7, LLY, LBZ, & LMM Duramax Diesel engine harnesses.