I'm working on upgrading electrical system. My car is '75 280z. My goal is : Replace Alternator to CS144 with removing external voltage regulator. Remove Shunt. Add extra fuse with install Maxi-fuse box. (75 has only 2 fusible link) Add ignition relay (75 does not have it) Swap Ammeter and Voltmeter My '75 280z has only 5 wire for external voltage regulator. When I googled, several people encounter issue for the missing #1 wire, which is green/red colored. Blues web sit