1988 cutlass ciera electrical problem

I have a 1988 cutlass ciera SL 3.8L with a problem. One day my radio, electric locks, dome light and horn all stopped working at the same time. I think that is all that is affected. Fuses are fine for all these accesories. Is there some master fuse that connects these particular accesories? My inspection is due this month and I really need to figure this out! Thanks all!

Yes, the main battery maxi fuse is in engine compartment fuse box. At passenger side. It connects to I/P fuse block. It rarely blow. So it could be also a bad contact on this fuse connectors.