Ok so I have fitted a python alarm to my 2002 7.3L f-250 as standard my truck had remote central locking but no alarm etc, everything works except when I lock the truck the alarm goes off after about 15-20mins every single time and every time it takes exactly the same amount of time, I checked the status led and it tells me it was triggered by a door, so I disconected the wire to the coor trigger and the alarm does not sound anymore.

The left and right door trigger's on the f-250 are on seperate wires so I conected my alarms door trigger wire to both of them by diode isolating them. there must be something that makes the alarm think that the door is open after 20 mins of being locked.

Like I said I cut the door trigger wire to the alarm and now there is no problem other than my alarm is not monitoring the doors, so there is nothing wrong with the alarm itself.

 

The VSM goes to low power mode and the voltage in the door sense wires goes from 12 to around 4v. This is enough to trigger most alarms. You have to use two diodes per door wire. I'll try to find the diagram, but this is what your up against.

 

Here it is, this will fix your issue.

http://www.the12volt.com/installbay/..._isolation.pdf

 

Ahh thanks for the diagram.

very much appreciated