Ford F150 - Dinging bell alarm in 1990 F150?

Hello all,
Sorry to have to ask this question, but I never got an owners manual and the crappy Haynes repair manual
doesn't have a word about it (at least that I could find).
Last night on the way home a ringing bell started sounding. There were no doors open or ajar (since that is what the bell sounded like to me) and there were no "check engine" lights on. My oil pressure seemed a little lower than normal, but it always is rather low. After about two or three minutes the bell went off. Never came back on. (Btw, I was NOT
drunk
Any clues/advice?
Thanks,
James

I had a 92 Bronco that I washed and had a pin hole in the rubber boot on the door light switch ( dingger button ) check this out , it may just need drying out or replacing.

Thanks Bama! I hadn't had it happen since so I still
haven't a clue...although it WAS raining that night
jim

Your driver's door hinge is worn, which has caused the pin switch to be maladjusted. The missing plastic sleeve for the door strike bolt allows the door to bounce & rattle, which is why the condition is intermittent.

There are hinge repair kits available at most parts stores, and many people on FSB like them, but I prefer to replace the whole hinge. It's more work, but I like stock parts.

Aligning the door isn't easy, but I think it's worth it because it really "restores" the truck more than you might think.

Readjusting the pin switch is easy: just open the door, carefully grab the end of the pin with some pliers, & pull it straight out about 1/4". The next time you close the door, it'll reset itself. These pics show how to reset them in a vise, but it's not necessary to remove them from the truck.