2000 Grand Cherokee Alarm Add-on

Hi,

I'm new to the forum but it looks like there are a lot of people who post in here that are well educated on car alarms.

Basically I would like to add-on an alarm system to my factory alarm.  I want to add a shock sensor and piezzo buzzers to start with.  I was told to look into buying a DEI Hornet 700T and that it would integrate into my factory system very well.  I did some research and it looks like it would do exactly what I want.  The problem is, I have never installed a car alarm before and as I was reading the installation instructions for it, I realized that I would be taking off door panels and things I am not familiar with. 

So more research followed, and I came across the JDL  (Jeep Data bus Doorlock Alarm Interface).  I haven't found a good explanation of it, but this is what I have come up with so far... any and all corrections would be appreciated:

The JDL would get connected to the diagnostic port under my dash and from there would monitor all door locks and pin switches.  When a door is opened or the locks are unlocked (with the alarm active), the JDL would send a signal to the 700T on the doorpin input setting off the alarm.

Now that is pretty much would I would like to happen, but I'm not sure if it is in fact possible.  I noticed the JDL needs inputs for 'door lock, drivers door unlock, and all doors unlock' and I'm assuming the 700T needs those same inputs.  Would it cause a problem if one of them armed before the other one??

If anyone has had experience installing either of these systems, I would really appreciate it if you could give me just a brief overview of how it would all work.  Thanks so much.

-Justin

I've been looking around some more and have read about a DEI product, the 455J that seems to have the same functionality as the JDL. 

Does anybody know if there is a difference between the two?