Cadillac Repair: security light, cadillac deville, type car

Question
Dear Kindly Volunteer, PLEASE HELP!!
Cadillac Deville 1991 - in the process of acquiring it from a "friend" (I hope)....
The security light stays on after the door is locked (pressing the lock which locks all the doors at once and shutting the door) I cannot find any way to get this light to totally turn off. The problem is it seems to run down the battery after about 2 days of not starting the car. Then the car is totally dead and has to be jumped. I can't figure this out. I also tried just locking each door one at a time manually, the security light blinks and doesn't stop.
What is going on? I never had such an "automatic - power type car before - is this just going to be too much trouble?
Everything else seems ok and it only has 98000 miles on it.
Very frustrated, please help.... Thanks, Christine

Answer
Inside of each door and the trunk is a small switch that opens and closes as the door locks are engaged and disengaged. In all probability one of these switches is faulty and or damaged. All these switches need to be tested and you will need pictures and directives showing you how to do this or giving the information to your mechanic so he can perform the test procedures.

You will need to e-mail: onlineautohelp@msn.com as pictures are NOT allowed on this website.