Bad or failing batteries can cause the symptoms described. I would get it tested at another outfit to be sure! Maybe when voltage gets low the locks and horn go haywire?
Sounds like it could be the power module?
I would also suspect the radio/cd player. I have heard mine making noise 5 minutes after vehicle has been turned off. But the real way to track it down is measuring amp draw at the battery while you pull fuses.
06 kj 3.7l, 6speed manual, np241 command track
91 yj 2.5l, ax-5, np 231 3 inck lift, 31'' mud rovers
12 kk 3.7L, 42rle, mp1522, d-30, 8.25.