67 Dart Conv. - No Tail Lights, Park Lights, Flashers

I have power to the headlight switch via both the black tracer (L1) wire fed by the Q3 Fuse Block Feed,

lets see if this is just a misunderstanding.

Both L1 and Q3 wires get power from the main splice.
L1 feeds terminal B1 on the headlight switch (headlights).
Q3 feeds two (sometimes three) fuses in the fuse block.
One of the fuses is wired to the B2 terminal on the headlight switch. The same fuse is wired to the hazard and stop switches.

1707784945119.png

And then the fuse box something like this
1707785032944.png

This should get you a step toward narrowing it down.
If the Q3 feed is hot, then the question whether the pink wire D31 to the hazard switch or L8 to the Headlight Switch B2 terminal is hot.

We can get into the headlight switch and steering column in another post. But the problem may be before the switches.