We’ve a 1989 VW Vanagon, which simply decided to lock it’s doors on it’s own. More importantly - they don’t unlock unless you grab the plastic rod on the inside, and pull very very very hard while opening the door. And this doesn’t always work. Kind of scary to drive it.
sounds like you’ve got an electrical short in the door. maybe a crimped wire?
unless you’re talking manual. my 87 is manual locks. in that case…?
If the door locks are electric, pull the fuse. If they are vacuum operated, as some later VWs are, disconnect and plug the vacuum line. The locks should still work manually, but not automatically. Who want’s to be locked in their own car?
Sorry; wants, not want’s.