disabling auto door locks?

About to buy a 1997 F150XLT, but the auto door lock system is locking and unlocking the doors at random. I don't have the truck yet and so no manual either. Is there a way to disable the auto door lock feature? I've read how to do it with certain other model Fords, but not with the F150. If anyone knows, I sure would appreciate you sharing your knowledge and experience.

Thanks