replace the dome light switch and in most ford probes the light switch is connected to the headlight switch and operates both the dome and the lights and has a delay timer and goes off after 5 to 10 seconds and is a easy fix too and can be bought at a junk yard for a very low price and isn't...
i know that you can go to the library and check out a book on this truck and you can also go to the parts store and buy the book on the truck too as that would be the best way to go and the cheapest and i bet it isn't a major fix i bet it is a simple fix and will be well worth the search