Hi Charles, finally found your message. I learned something new. My '86 started doing the same thing when it was less than a year old. The factory fix was to disconnect it. There was never a replacement or modification. Please note that this disables only the motion/tow feature and does not affect the rest of the alarm, (you might test it to be sure).
I do not know if the later models have a motion/tow sensor incorporated in the alarm system or not.
Hope this clarifies it, regards, Ed
By the way, the way to check it is to roll down the drivers window then lock the car, reach in and open the door from inside and/or pop the hood. The alarm should sound. E