I have a 2000 Oldsmobile Bravada

I have a 2000 oldsmobile bravada. The guages and interior lights are not working and car will not start. The brake lights are staying on at all times.I have check fuses and relays. At first atc mini fuse and aslo the maxi ignition fuse were blew. I replace them both. Then I tried swapping the bcm (body control module) and Tccm (transfer case control module)still nothing change