Alternator wiring question

[Gbeck]

I hope somebody here can confirm my thoughts on this or point out where I'm wrong. It has to do with the wiring of the alternator.

Some background info ... I have a Gen 2 Coyote engine from a 2015 Mustang, the Ford Coyote Control Pack and the Ron Francis Chassis Wiring Harness. I have the power cables from the Mustang, including the battery cables and the cable (4 gauge I think) that runs from the alternator power lug to the starter.

The connector on the alternator is connected to the Coyote Control Pack plug (3 wires; red, blue, purple) as specified in both the Ford and Factory Five instructions. That is not the issue.

The alternator connectors on the RF chassis harness are different from the FFR Roadster Coyote Engine documentation (15471 Rev B) and they do not match up to the alternator connectors. Judging by these connectors I have an older version RF chassis harness. It matches the Revision L, March 2012 documentation on the Factory Five Instructions site. Instead of having a single ring terminal (as described in FFR's Coyote install instructions) it has two connectors and four wires. Here's a pic of the alternator connectors on my RF chassis harness ...
Alternator Wires by Team Limer, on Flickr

The RF harness wiring diagram shows that all of the red wires pictured (the two 8? gauge wires and the smaller red wire in the other connector) are all connected together in the harness and run behind the dash, then out to the main power lug on the starter where it joins with the positive battery cable, the main fuse box feed and the ignition switch feed. The brown wire connects to the ACC terminal on the ignition switch along with the ACC feed to the fuse box.

I think it would be better to use the 4 gauge cable from the Mustang to connect the alternator power lug to the starter power lug through a 150 amp Mega Fuse. Then I would disconnect (or maybe remove) the pictured wires from the harness.

The red wires would be replaced by the 4 gauge cable.The brown wire would also be eliminated. I'm not certain because the FFR Roadster Coyote Engine documentation does not say to connect it to anything, but it also doesn't mention that it's not used.

Good or no?

[Gbeck]

I got a reply in the Factory Five Builders group on Facebook and thought I'd record the response here for the next guy. The replies suggested that I use the Mustang cable to run power from the alternator to the starter instead of the charging cables in the Ron Francis harness. It's certainly true that the RF wiring is quite a bit smaller gauge than the Mustang cable. I identified the wires in the harness, removed the connectors, capped the wires and tucked them away behind the dash. I would like to have removed the wires from the harness entirely, but that's just not practical at this point.