Honda Accord seatbelt alarm

I have a 1988 honda accord. My problem is that the seatbelt/door ajar light stays on, and when I get above 10 miles an hour the seatbelt alarm goes off. It started last year. If I opened and shut the door it would shut off
most of the time. When it started getting cooler (40 degrees or less) it would not go off. All winter it did not go off. Once it started getting warmer it started going off again. Now that it's warmer (above 40) it will not shut off. If I stop and open and shut the door it will stop until I get above 10mph. I am hoping you can tell me how to bypass the alarm. It is high pitched and very annoying. I could not find a fuse that corresponded to the alarm. Thanks, Mike
P.S. I always wear my seatbelt so that is not the problem!