Loose/corroded battery connections. Remove and clean EACH end of every cable to both terminals of your battery at EACH end. Should take you an hour or two.
Corroded ground busses. Under the carpet next to each front door bottom sill is a group of grounds connected to a bus connector. Inspect these for wetness and corrosion.
If neither of these work, use the TECHINFO (link at the top of the page) procedure to remove your cluster and clean the connections.
Odds are very good that one of these is your problem.