69 Dart short

What you might do before you pull the switch is to do a good thorough inspection of the front lighting harness, from each parking light, follow it back all the way to the bulkhead connector, looking for damage, pinched harness, etc.

Since the light switch must be on and since you disconnected the rear harness, there is not much else. The tail lamp power goes down to the kick panel connector you disconnected. The parking lamp power goes to the bulkhead connector, into the engine bay lighting harness, and out to the parking lights.

Also if you have not pull the front lamps apart and inspect the lamps, the pigtails and the sockets and insulators inside the sockets, as well as insulation coming out the rear of them.

The only other thing the park circuit supplies is the dash lamp dimmer. If the front harness does not show up anything, it might be shorted as I said earlier. Start by checking the "INST" fuse which is at one end of the fuse panel. It may be too large. Remove it for testing

The way the dimmer/ dash lamps works is this:

When switch is in "park" or "head" the dimmer rheostat is hot. It feeds "'dimmed" power out on a tan wire TO that INST fuse, and from there to all dimmer controlled dash lamps via orange wiring.