I know this has been mentioned before but any of you electronic wizards come up with a mod for our door locks. there must be a way to tap into the wires and sound the horn or something when we lock or unlock. Maybe some soft of relay or something. Is this a very hard thing to come up with or just to expensive or just not worth the effert. Just wondering!!!

 

Get an alarm. That will do it.

The relay thing will work if you find the remote brain and then tap the door lock output wire with a trigger lead to a relay that connects B+ with the horn.

However, with equal effort you could install an alarm.