Remove and clean all the wires on the one relay post that has the battery positive cable on it
Those wires are all fusible links
One of those wires sends 12volt to the ignition switch, which will be your next stop
Ignition switch is under the steering column above brake pedal
It is a Slider switch
When you turn the key a rod inside the column slides the ignition switch into its 4 positions, ACC, OFF, RUN, START
Only ONE wire from that relay post feeds this switch, a Yellow wire at the switch, splits into 2 wires at the switch
If dash lights don't come on with key on then either the Yellow wire has no 12v or ignition switch is not working, broken
This Yellow wire also powers 4-way flashers and brake lights, see if they work, if not then yellow wire is bad in engine bay somewhere, or its fusible link is bad
If 4-ways/brake lights work then ignition switch is most likely bad