Look at the wire gauge that feeds power to the TFI - that is your clue...I have been swamped at work and have family coming in tomorrow, I got very little done but I will show you my method for making a wiring harness... this is how I learned to make them when I worked in a panel shop as an IBEW apprentice..
of course we have all made a harness before, but sometimes it's hard to find the right tape or everything ends up unraveling when the heat gets to it. I used standard imperial sized wire loom, black cloth friction tape, 4" black tie wraps.
Most people omit the tie wraps, I add them simply to stop the tape from unraveling. I don't like doing the knotted end like some prefer for me it just looks odd.
You may omit the cloth tape and just tie wrap if you prefer, I think it adds a nice oem look.
Obviously I am far from done, the rest of the harness must be finished on the car.
@jrichker do you happen to know the current rating of the 12v circuit on the TFI module? The swap suggests a 20 amp circuit for the coil packs. I will add it to the relay box I am installing if it is not adequate.. thank you.
Wire size current table:
18 gauge wire = 5-8 amps
16 gauge wire = 10-12 amps
14 gauge wire = 15-17 amps
12 gauge wire = 20-25 amps
10 gauge wire = 30-40 amps
8 gauge wire = 50-60 amps.
