74 dart can’t get a spark

If you have power to the ignition switch connector probley the splice is OK. Failure of them is rare. I would reconnect the switch and start looking at output. The blue run of course for sure. See, it's common for the switches to wear internally and the contacts "waltz around" inside the switch."

There's a very good writeup around this site somewhere on how to service the ts switch and ignition switch