Burnt Wire

Ok. Good.

One approach would be to disconnect the S2 wire from the relay and the Ignition 2 wires from the ballast resistor and coil.
Turn the key to Start.
If the lamp glows, then fault is further back. If it doesn't glow then its one of the devices you disconnected.
upload_2021-2-26_18-19-57.png

I'll be back in a few hours. If 67Dart273 stops in, he can help if you need.