Probably 2 things, both are probably a symptom of being wet inside.
Remove the dash and clean the electrical connectors with a qtip and rubbing alcohol. Let em dry up good, then apply dielectric grease to keep water out and ensure a good connection.
THEN you will need to likely replace the clock spring on the steering column between the steering wheel and the column itself. If it gets wet, you could see symptoms like you are describing. Kinda ironic in a vehicle designed to go anywhere eh?