12-09 Wiring Pt 2 - Engine

The engine is a Mustang 2007 4.6L. This is convenient because Ford Racing makes an engine control module for this year range (I think it's 06-10). The control module utilizes the stock engine harness which was designed for the computer to be up front on the passenger side. However, I wanted to mount to computer under the dash. To do so I would need to run the wires back.

I started by opening up the looms to figure out what wires needed to run where. The first two pictures show the mess this turned into.

Quickly I determined that I would need to extend some wires - but only about a dozen - including some of the injector and coil wires. So I needed some patch wiring, but good quality stuff. I did quite a bit of research to determine the right type of wire to use and couldn't really determine what was used from factory. So I went with an overly high-grade to be on the safe side. In the end I ordered two spools from Del City: 100-ft (overkill!) of SXL Cross-Link Wire 14GA and 100-ft (used a good bit of this) 18GA. The wire has a noticeable white inner lining (between the black insulation and the wire strands). While this was undoubtedly a higher grade then I needed, I'm glad I erred on the safe side.

I also bought a fresh spool of solder, a long tube of shrink wrap, a quality wire stripper and a heat gun (well worth it!). By the end of this job I have gotten pretty good at soldering. For those interested - here is how I did it. I stripped the factory wire and cut the length of new wire. So i wouldn't forget I clipped two pieces of shrink wrap and feed them onto the patch wire. I then meshed the two wires together (intertwining the wires) so they were parallel. Getting these wires to stay in place was sometimes a little tricky but I usually managed with coercing. To solder I got the iron nice and hot and held it against the exposed wires. Once they were warm I lightly touched the solder to where the iron and wires met. If done right it would instantly melt and spread smoothly across the wires. Making a solid and clean junction. I would then slide the shrink wrap over and heat it into place.

I proceeded to clip and solder the lines and reroute the bundle. I had considered running all the wires under the intake manifold, but I decided not to for two reasons. One, there is a lot of extra wire and I didn't want to have it flopping around against the heat of the engine. There doesn't seem to be good locations to create any mounts. Two - and more importantly - I didn't need to open the driver side looms so leaving them alone would save me quite a bit of work.

After that was decided I ran into my next challenge. One of the wires that needed extending was blue, foil wrapped. I did some research and discovered this is the shielded crank position wire. The shielding is in place to prevent any interference from causing incorrect readings of the crank. Inside the foil are two wires in a twisted pair configuration and a bare ground. I also discovered that the blue (outward) side of the foil was non-conductive. Again, some research and asking around, I came up with a plan. I spliced in two twisted wires. I then stripped a wire bare and spliced that in (no shrink wrap). I then cut long strips of foil and wrapped the entire configuration. Finally I put a long tube of large shrink wrap (I actually ran the wires through the shrink wrap before soldering) over the entire addition. This would prevent any other grounding from the exposed foil.

Finally I used mostly the stock looms and liberal amounts of electrical tape to give the clean look (last picture).