doors do not trigger alarm
      Printed From: the12volt.com
       Forum Name:  Car Security and Convenience
       Forum Discription:  Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
       URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=118942
       Printed Date: November 04, 2025 at 5:49 AM
      
 
  
      Topic: doors do not trigger alarm
      
  
      Posted By: stevenje98
       Subject: doors do not trigger alarm
       Date Posted: December 29, 2009 at 11:58 PM
      
  
      
 Doors not triggering alarm when open.  None of the doors will trigger the alarm. I tested all doors by manually unlocking each door trying to get the alarm to trigger. 
 2001 Suburban 
 Installed AudioVox 997a 
 Installed drivers priority lock unlock relays . The lock system works fine. The dome lights work also.  Everything works except the doors don’t trigger the alarm when open.  The alarm show active on the LED and the shock sensor works, and the remote start works . The hood pin trigger also works.
  I Installed all door triggers to the Alarm Negative Door Input, and placed diodes on all the  door triggers. I installed the diodes with the cathode band facing away from the alarm unit . Did I do this backwards?
 I connected to drivers  TAN door trigger  B4 ,purple plug.  And passenger doors Blue white Pin B11. Also connected to alarm negative door trigger input  is the door trigger to the rear cargo doors, these are also negative. 
 There is also a ground pulsed output to shut down the radio connected to the Alarm Negative input.
 Do I need to  diode the Lt green Arm\Disarm?
  
      
 
  Replies: 
       
       
      Posted By: hydrodancer91
       
      Date Posted: December 30, 2009 at 12:32 AM
       
      you wont have to use a diode on the ltgreen disarm wire. and if all your bands on your diodes are facing the source of ground meaning the bcm you have all them in right and im assuming your using the pink/black for the rear door trigger so having them all diode isolated to the negative door trigger is fine. i dont quite understand what your trying to do with the rap shutdown? that might be your problem. and off the top of my head i cant remember if a 01 is still one where you have to make sure the domelight overide isnt turned on. so you might want to check for that by the headlight switch that might be in the earlier models i always forget when they stopped with that. which shouldnt really matter anyways since you got individual triggers. 
       
       
       
      
       
      Posted By: howie ll
       
      Date Posted: December 30, 2009 at 4:06 AM
       
      Have you tested at the alarm plug, i.e. DMM red lead to a constant 12v+ source, black lead to door trigger input, set to 20VDC then open each door in turn. If you get a reading, there's either something wrong with the alarm or its programming. Yes I concur, the diodes are correct.
 Sorry I can only think of elimination testing. 
       
       
       
      
       
      Posted By: stevenje98
       
      Date Posted: December 30, 2009 at 12:59 PM
       
      I pulled the wire  for  ground pulsed output to shut down the radio. no change. 
 
 I'm going to test the alarm plug for voltage.  do you think the 2 relays for drivers priority need some diodes?  I thought i read someplace on the board about that. I'm going to have a search on that to find it.  also I wonder If I grabbed the correct wire for the door unlock motor for driver priority. There are two tan wires in my kick panel. I did a conductivity test and put the meter on the door trigger and the wire where I have the relays connected to the unlock motor.I did get a reading and sound. I don't think the door trigger and unlock motor are in parallel are they? 
  
       
       
       
      
       
      Posted By: stevenje98
       
      Date Posted: December 30, 2009 at 1:36 PM
       
      I just tested both 12V sources at the plug with my DMM fluke meter.
 
 I get 0.5V when meter neg-lead is connected to the door trigger input. there is no change in voltage it remain constant with the all door opening and closing.  
 
 I did notice that the factory security light flashes " Security" in the info center on the dash every time a door is open. 
 
  
       
       
       
      
       
      Posted By: stevenje98
       
      Date Posted: December 30, 2009 at 4:59 PM
       
      Found the problem.  It’s the Diodes !
 
 Some  of them worked some did not. I  found this  out when I started using more from the pack to see if it was the Diodes themselves.   I  swapped some from the package and installed them again. Some worked some did not when I test the alarm.    
 
 I bought these from a national chain  alarm shop.  I won’t  mention the name on the board.  No name brand package diodes. I decided to chuck them all in the trash.  They were made in china.  I was P*** at this chain. I did not call them either. Let them suffer from the return service work I'm sure there getting now. 
 
 I went out and bought some NTE Semiconductor 1N4001 Diodes 50V 1Amp.  I purchased then at  local all electronics part shop $ 12.00 for  a pack of 12.  I replaced all of the diodes from the alarm shop that  cost me $ 16.00 for ten.   The NTE Diodes worked the first time. I tested all 12 of them to make sure they all worked.  
 
 What a waste of time I went though ,because of bad diodes. I never heard of bad diode until today. 
 
 Thanks everyone for your help. I did lean a few things on trouble shooting alarms from this post. . I know  this gained knowledge will serve me well in the future.
  
       
       
       
      
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