My 1992 Thunderbird suddenly developed a seat belt issue. Even though the seat belt(s) get firmly buckled and the door restraint(s) go to proper position the seat belt light does not go out. The chime stops, but the light remains on. I've tried with and without a passenger to see if the passenger sensor may be at fault, but still nothing to solve the issue. Does anyone have a clue to even begin trouble shooting such an issue or am I going to have to visit the Ford mechanic to have this resolved?