'fleet/taxi' wiring bypass diagram.
I'm not sure why you'd want to go through the hassle of that deal. Looks like more trouble than it's worth and cutting up a harness with other solutions out there.
I already have the harness apart from putting new bulkhead connectors (cleaned them all and replaced a few terminals in them as well) on both sides of the firewall. For grins I figured I'd look up what the 65 amp alt (AKA taxi) wiring required before I closed up. It
appears (still not sure I'll do it) that it wouldn't require much extra on my part to make this change.
I'm not sure where cutting up the harness is required. The diagram shows where the only bulkhead wire (A1) in this set up runs on both sides of the firewall on the specific '72 connector. It enters and exits the firewall at connector slot 18. On my '67 that would be connector slot P.
My bigger (not clearly stated) concerns are:
1) The gauge changes for the A1 wire (fusible link notwithstanding)
2) The 16ga size of A1A wire (starter relay to red terminal on the ammeter)
3) The terminal block where the 6ga R6C wire from the alt splits to A1 and R6B. I've
found a p/n 1842267 which I think is the terminal block for the L/N 65 amp alt (not
sure if a must have)
And, as was explained earlier, the 6ga black wire from the alt to ammeter is that size for very good reason.