74 dart can’t get a spark

White? Don't know what you are referring to unless you mis- read the white CONNECTOR. This is a troublesome connector in the engine bay that separates the engine connections harness from the firewall harness. Part of the reason it fails is the main alternator output wire goes through it before it goes through the firewall.

This is starting to sound like the welded splice is bad. Make CERTAIN your test lamp is working and grounded. There is only one wire that is hot going to the ignition switch connector--the large red