The 5.9-liter common rail Cummins is one of the most popular swap engines out there, but there’s always one big hurdle: the wiring. Adam Spragen of the Spragen Built YouTube channel just walked through a clean solution for that headache, showing off a full standalone 5.9L CR Engine Harness Installation from Diesel Conversion Specialist (DCS) that takes the guesswork out of the job.

Out Of The Box And Onto The Engine

Spragen started with a bare 2006 5.9-liter Cummins and showed how the DCS kit is essentially two main pieces: one harness for the engine and one for the chassis. The first thing he pointed out was the quality of the instructions that came with the kit. “They do a very good job with pictures and labeling everything for you so you know which connectors go where and what connectors do what,” he said, showing how each plug was clearly identified.

A Clean 5.9L CR Engine Harness Installation

With the main plugs connected to the engine control module (ECM), Spragen laid the harness over the engine and began plugging everything in. He methodically connected all the critical sensors, including the injectors, oil pressure sensor, MAP sensor, and the cam and crank position sensors. Using the provided clips and zip ties, the 5.9-liter CR Engine Harness Installation resulted in a professional look, keeping the wires safely tucked away from hot or moving parts.

The “Must-Know” Details

Spragen made sure to highlight a couple of main points for anyone doing this swap. First, you still have to wire in your factory starter circuit. But his most important warning was about the factory security. “You put this harness on the truck, you are going to have to have it tuned to bypass the security that’s built into the computer on this,” he stressed. On the flip side, he showed off the kit’s best feature: integrated wiring for an aftermarket lift pump. “So, that gets rid of some of that messy wiring that you would have with a FASS, Air Dog or a Raptor,” he explained.

A Swap-Ready Solution

Watching Spragen’s install, it’s clear that this harness is a game-changer for Cummins swappers. It takes what is arguably the most tedious and intimidating part of the job and turns it into a simple, plug-and-play affair. The final verdict from the video is that the Diesel Conversion Specialist 5.9-liter CR Engine Harness is more than just a set of wires; it’s a well-designed, complete solution that saves time and eliminates headaches for any custom builder.