JBelmont

Hoping someone may know what I can do to combat this...

2003 F150 extended cab Lariat, had factory keyless...

I installed a DEI Avital alarm/remote start to combat my local thieves who have broken in 3 times... I followed a few online guides on wiring but every time I arm the alarm and the doors lock, exactly 45 min later I get a door open alarm... This only occurs if I use a door lock - I can override it once it goes off and it wont ever sound again until I lock the doors... It's not dome light as it isnt hooked up, but the trigger is a ground from the doors...

Any thoughts? Everything else works flawlessly - just tired of the late night get home from work and have to wait 45 min before I go to bed!

Thanks!

Jeff

knightfire83

Your problem is with the BCM module. It controlls the dome light, door ajar dash light and many other items. I had the same problem on my '97 when I installed a alarm/remote start.

When active the module puts out a small voltage on the door sense wires (door switches.) The alarm sees this voltage as normal closed doors. After 45 minutes or so the BCM goes into a sleep state and discontinues this voltage.

Effectively the BCM becomes a ground on that circuit and triggers the alarm just as an open door would.

Your fix is to install Diodes as this picture shows: http://www.the12volt.com/installbay/.../212_diode.jpg

This prevents the BCM from back feeding as a ground and both the alarm and the BCM are independent of each other. Diodes have to be installed with the stripe (polarity) as shown or it will not fix the problem.

I installed 2 of mine at the alarm module, and then one behind each kick panel that has the wires leading into the doors.

It's a pain to have to do, but once fixed it is oh... so nice.