The new engine was pretty clean when it arrived but I still took time to give it a detail cleaning with Simple Green and a scrub brush. I had to be careful not to break anything since the plastic on all of these engines get brittle over time. Once the engine was clean, I started cleaning the engine harness. I cleaned and inspected the harness at the same time. I had more busted harness plugs and broken wires than I would have thought. I will have to take some time to repair those before I install the harness on the engine.
The harness installation is straight forward for the most part. It’s pretty obvious where the plugs attach once you lay the harness on the engine. Beyond the injectors and coil packs, it took some time to figure out what went where. None of the repair manuals have this information. The wiring diagrams have which wire goes where but it doesn’t illustrate the plugs. I wish Audi made it simple with colors. Some plugs did match up with colors, but there were a lot of black plugs. I did find a thread on Audizine to help clear up some of the mystery. The one plug that I never found is the one for the oil pressure sensor that is above the oil filter. After speaking with that company I order the engine from, the harness shipped with my engine isn’t the original harness from that engine. I thought I was buying an engine plus all its components from one donor car. If it was all sourced from the same car, it would have taken all of the guess work out of matching things up. As far as the oil pressure sensor connection, I think there is a sub harness for that connection. I still don’t know where it would plug into the car or the main harness. I guess I will find it at some point during the project.
The picture below shows the oil pressure connection behind the dip stick. Apparently this connection can be in various places on the engine depending on the year of the car or the transmission mated to the engine. From what I could gather, there is a sub harness for this but I still can’t understand where it plugs into the car or engine harness.