my 89 420sel came with an alarm system.It has a seperate horn which seems to be under the batery holder. The problem is the prier owner installed a keyless entry with its own alarm consisting of a siren which was working fine until today. I started the car this morning and the factory alarm [horn] went off for no aparent reason the only way to stop it was to find the fuse in the fuse box and remove it. The problem is that fuse also controls the door locking system and other things. Is there a wire i can remove or a relay to completly dissable the old system.