Unkut,
Thanks for the replies. I will look into it. I feel confortable with it. I've done many car stereo and alarm installs (used to work in the business). What I like doing these days is integrating as much of the stock as possible. I'm aware that cadillac has the Pass Key system, bus system, etc. These could all flake out with aftermarket parts as with the radio interface modules that are out there. What I was really wanting is a schematic showing where the door sensors enter into the alarm, computer, etc. I was simply going to install the sensor and tap into one of those lines and isolating with a diode. I've done this many times in the past with stock alarm systems or with alarms that don't have accept those type inputs.
Bobby
There aren't any door sensors bro lol. What type of alarms have you installed that had specific door sensors because I've never heard of such a thing? When you open the vehicles door it activates the interior lights which in turn triggers the alarm. Some of the more advanced 2-way alarms will indicate a "Door" violation for interior lighting and a "Sensor 1" for the Shock sensor, but the doors aren't specific like say a hood/trunk pin would be. Your are right about the VATS or Passkey system, for schematics I'd say drop by your local dealers service dept., or you could try you luck researching it online. But your local stealership will pull it up by your VIN which will reduce your error margin dramatically lol!
On some vehicles, tying into the "door" is as simple as connecting to the wire of the dome lamp that changes from (+) 12 VDC to ground, or vice-versa on Fords, when any door is opened. However, some vehicles have a dome lamp delay and/or an auto off feature. On many of these, you will want to locate the trigger wire(s) that will show either ground or (+) 12VDC when each door is opened, that is not affected by the dome lamp being on or off.
On the vehicles that have two separate (-) door triggers that are isolated from each other, most commonly found on newer GM vehicles, you will need to use two 1 amp blocking diodes for all doors to trigger the alarm.. One trigger is for the driver's door and the second is for the rest of the doors. If you were just to connect to one of these and not both, one or more doors of the vehicle would not be protected by the alarm. If you were to tie each of these together without the blocking diodes, some features of the vehicle will no longer function properly like I said before.
Those direct plug-in alarms like the radio interfaces are B.S. (junk) and you may as well go grab a BULLDOG system from your local Autozone lol! I know teenagers that can manipulate those and can't even pass a math test, lmfao!!! I'm not sure if money is your primary concern in this situation or if your simpily just a hands on type of guy. Either or I sure hope you make a wise decision and the best of luck to you!!!