I have searched and searched and cant find my answer and a DIY anywhere. I want to be able to hear the horn, or lights flash, or the cornering lights and tailights to flash, or a combination of, when you arm and disarm your FACTORY alarm with key. Lastly, I also wanted to add a lit interior when diarmed as well. Does anyone know how to do this or can someone post a link?

Again, I have searched and found nothing, just some people saying use relays, but nothing further. Thank you! I have 1992 SC400, if that matters.

Its not a simple DIY project. You will need some basic to advanced electronics knowledge.

You will need to build a relay circuit off the lock and unlock wires to trigger the flashing lights/horn honk. Additionally, in order to make the lights flash a flasher will need to be wired in series to the light output. Also, a timed output module may be needed as well although I'm not certain on that. I would need to draw the circuits out and think about it a bit.

This link may help you see how the circuits would be designed. The input feed for these circuits is a lead from an aftermarket alarm (siren output/lock output/etc). You should be able to use your lock and unlock wires as the input lead (trigger wire).

My advice though is to locate a local shop that is good with custom wiring and circuitry and have them tackle this for you.

Here's the link:
http://www.dlcparts.com/images/BoschGuide.pdf

I appreciate the link. It helped me understand the wiring thing a lot better. If you think you can draw me up a digram or something, please PM me. Thanks for your any help on this. This is more than what I have found!