My lights are gone... Help please.

[3/4ton72heavychevy]

I've got a 72 chevy c20, and for the past few days my truck has been taking 4 or 5 seconds of cranking before it will start. The radio will flash on and off while the truck is idleing, but will stay on fine when I am driving. Sounded like the battery going bad to me. Until last night. I start the truck and my headlights come one, but my interior light, dash lights, and taillights will not turn on. Even when I am driving.

Any ideas on what the issue is? bad fuse maybe? any help is appreciated.