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

Mopar_Parr said
L8 is hot with the door shut until the brake is applied, then goes to zero volts.

Did you note how much current the ammeter was showing when you did this?
and

Mopar_Parr said
Steering Column harness disconnected, door shut, key off the voltage at L8 is 12.2v, turn the key to the accessory position it drops to 11.5v.

this?

If volts go to zero at point of measurement, and the ammeter shows discharge, then current is flowing and there is a short or connection to ground before the point of Voltage measuremnt. The ammeter scale is roughly 40 amps at full discharge and 0 in center. Estimate based on that.