Usually the trunk lock mechanism draws enough voltage that it will have it's own Fuse. I would check that first before anything else. Most ALL my experience has found that the Fuse was burnt (an acceptable occurrence) usually from being harder to release from age and a need for some Lithium grease on the mechanism on the trunk assembly. I would check all the mechanical and electrical (Fuse) in the car before giving up and taking it to a shop. Many times, it can be fixed easily and more cheap than what you might think. Hope this helps.