2005 Kia Sedona Everything Electrical is going out

Radiator cooling fans stopped working--A mechanic rewired them and they are now working fine (this was about 2 months ago). Just last night got in the van and no A/C blower (possibly even the cojpressor clutch is not engaging), no headlights, and no windshield wipers. Is everything starting to go haywire? Where should I be looking--Have checked fuses, relays, checked for burned wires to no avail--no voltage at the relays and switches? The mechanic that worked on it before says it could probably be a computer problem--I did not think that the fans, lights, wipers, etc. Were routed through the computer?