i had the same problem on my 95. just spray some liquid wrench on the door latch. wd40 dries out over time. they get sticky over the years and the sensor thinks the door isn't fully closed.
my obsession is my 1995 Ranger Splash. 5/6 drop, mini notched, sporting 18x9 boss 304's
underdog line of fire, 66mm bbk tb, customized flowmaster exhaust, sport trac gauges, 8000k hids
"Minitruckers...Giving back to society...one fine at a time"