Slightly more work to disconnect interior door if that's preferred.
On the jamb side of interior door, find 2 wires feeding stationary part of contact. Probably have to remove molding. Disconnect and solder in a run of 2 conductor alarm wire from the 2 wires to new location where exposed contact will go on jamb. Connect to 2 screws on switch.
If you want to ADD the screen door, you will have to splice into existing wire near where you want new contact. Cut one wire and treat 1 wire of new extension that you add as a 'send' (to contact) wire; the other as a 'return from' contact wire. If you can distinguish wires (ie one gold color and one silver color), splice into same color wire as on interior door.
Another good forum:
http://www.diysecurityforum.com/
On the jamb side of interior door, find 2 wires feeding stationary part of contact. Probably have to remove molding. Disconnect and solder in a run of 2 conductor alarm wire from the 2 wires to new location where exposed contact will go on jamb. Connect to 2 screws on switch.
If you want to ADD the screen door, you will have to splice into existing wire near where you want new contact. Cut one wire and treat 1 wire of new extension that you add as a 'send' (to contact) wire; the other as a 'return from' contact wire. If you can distinguish wires (ie one gold color and one silver color), splice into same color wire as on interior door.
Another good forum:
http://www.diysecurityforum.com/
