Check all the fuses. I believe 18 and 19 are the ones for the running lights. They are after the switch, before the lights in the circuit. Check for power to the fuses from the switch, you'll need to turn the switch on to check this, and any connectors between them if not present.
Likely suspects are the three big connectors on the kick panel running into the fuse box.
They can loosen or corrode. Pin 12 in the big red one and pins 16 and 20 in the big white one are involved. The content on this site may not be republished without permission.