Here’s the story. We bought a 2005 Ram 2500 had a 5.9l cummins engine in it. The engine was already pulled and was put in the bed when we purchased it. It was the complete engine(turbo,wiring harness, ecu, etc). We then went to purchase a 2006 5.9l that was in a fire. We heard this engine run before the guy pulled it for us so we know it runs. We out the 06 engine into the 05 truck with the 06 harness and 05 ecu. When to fire it up and nothing. Looking around and have seen some things online saying that we should have put the 05 harness with the 05 ecu on the 06 engine. Does that sound correct? Anyone have any suggestions for us would be a huge help. This is my sons project truck and it would mean the world to him. Thanks in advanced!!