Stumped** 2001 Tahoe; Odd Electrical Issue..
 

Hello All....
I'm new & Yes, I searched first before posting:D

The skinny:

2001 Tahoe
Instrument cluster went wacky; only oil pressure & battery currently are working. My radio also will not power up.
The dash & radio back lighting is working, but my other gauges are all dead; from the tach to temp,speedo, gear indicator... DEAD!!

Other than the cluster issue, the vehicle operates fine..
I'm guessing my speed and gas levels, not really enjoying that, but....

The unit has on 2 different occasions started to work, only at ignition and would operate normally for 5-45 minutes.

Checked all fuses, harnesses for faults, none found.
I've reset the system (battery disconnected for 30+ minutes)
I've tried 2 different instrument clusters to no avail.
I swapped the Body Control Module, nada.
A scan tool gives no indication of any faults.

I've read plenty regarding what I thought were similar issues, but am believing this is unique?

Any educated guesses as to my issue?

I've been reading this forum on & off for the last 18 months (regarding my other vehicles) and am very appreciative of the knowledge that is shared here and welcome any suggestions.

Thanks!