Ignition woes

Last week you described measurents you made with the bulkhead and steering column disconnected, dome light on.
10.1 Volts measured at the fusebox hot buss (Q3 )and the steering column connector (J1)
3.7 Volts at the switched accessory connection (Q2A) in the fusebox
upload_2022-9-7_15-11-37.png
On Friday you were pulling fuses on the hot buss and noted
12.47 volts at Q2A-12BK with dome light and map light off.

Based on this, there is a short or maybe a backfeed, which for diagnosing can be considered a short.
Electricity is finding some path into the disconnected circuits.

With all of the steering column wires disconnected there should be no power available Q2, Q2A or any circuit that is powered through the key switch.

Remove each fuse from the switched buss to determine if the short is through one of those circuits. It would not be too surprising if it was related to the tail lights.