I noticed that my engine was intermittently "missing", as though the spark plug was not always firing. I took off the engine cover and found that 2 of the wire bundles leading to the spark plugs had their wrapping worn off, and I could see bare wires on a few of the wires. The wires are multi-strand and some of the strands were completely broken. I suspect they were rubbing on the underside of the engine cover as it was only the top-side of the wires that was worn down.
I spliced in some new wires temporarily (shown in the photos) and that seems to have resolved the misfires. I'm trying to find the part number for that wiring harness, but I haven't had any luck. Does anybody know the part number or distinct name that I would search for to find information online?
Edit : 2010 Ford Fusion Hybrid
Thanks!