Dash Gremlins - Electrical

Just a thought...

If you have a bad connection in the bulkhead connector it will generate heat. Heat makes metal grow(so to speak) which might make the connection better explaining some of your symptoms.

But my first thought was bad grounds, crossed wires.

67 dart has a factory known wiring irregularity,

1. with the key out of the ignition
2. Turn on radio (no sound)
3. Turn in flashers
4. Press brake pedal
5. Listen to radio

Some how the power gets bypassed around the ignition switch,

This type of back feed could explain the bulb glowing dim