reasons:
1. high current on all devices, these devices all share the same bus, so it is very likely that the CAN bus is damaged which resulted in excessive current drain.
2. when you pull fuse for each device, the ground is not isolated so the device with damaged CAN buffer/driver can still drain current
3. the dash cluster was dark for a brief period, this fits the typical symptom of semiconductor thermal or ESD breakdown.
4. the audio unit wants to calibrate upon power up, which means that it is not able to communicate with ECU through CAN bus.
to confirm CAN bus damage:
disconnect the battery, measure the CAN bus resistance to ground from OBD port, according to specs the resistance should be around 100ohms
to isolate the damaged device:
pull off wiring harness from each suspected device and measure CAN bus resistance
