Viper 550 ESP in a 2002 Ford 250 Crew Cab

I have posted 2 questions here and the answers were right on! thanks...I am installing a Viper 550 ESP in a 2002 Ford 250 crew cab. The problem is with the door trigger. As some of you guys know, all doors input into a Vehicle Security Monitor (VSM). All switches in each door is built into the latch. All switches read grounded when the door is CLOSED; this is checking each wire separately at each door. And yes, I can tie into the dome light circuit, but it has a delay, which will set of the alarm if the auto start is used.

So, the question is can I use the individual door switches that are normally grounded, through relays or what ever to input to the alarm door triggers and if so HOW???

thanks in advance

Chris,

The alarm trigger input can be either ...connections for (-) and (+).  The (-) input cannot be used with a direct connection because the  door switches are normally closed...triggers the alarm with doors closed. Any thoughts?

thanks

You could still diode isolate the four and put them through a relay.  Same theory applies just with a reversed polarity.   Look here to see how https://www.the12volt.com/carsecurity/page5.asp#adsensp

 I dont see the problem here excatly but if this problem with the vsm exists with the door trigeres, Why cant you find your door trigger wire in each of the doors and cut the wire, then place a diode inline of the cut wire stripe facing away from the  door and connect the purple (+) viper door trigger wire on the side of the diode without the stripe for each door triger wire.

In this way of hooking up the triggers, the diodes should block whatever you dont want the viper door trigger wire to see from the vsm.The viper wire should only see (+) when any of the doors is opened but not see any thing comming from the vsm side of the wire.

Use the (+) trigger on the alarm and double diode isolate with (2) x 6 amp diodes wired in parallel with the cathode band facing the alarm system. No need for the relays if you already have a (+) trigger input on the alarm system.

Thanks for the replys. Please hang with me on this. I understand what both of you guys are saying, and infact that is what I started with.

The (+) door trigger input (purple) on the alarm requires 12+ to activate

The (-) door trigger input (green) on the alarm requires a ground to activate

I have a ground coming from each door with the doors closed (the door switches are closed with the doors closed, not open. I have checked this at the switch in the latch.

So, I can't use either input to the alarm without changing something. This is what's got me stumped.....any ideas? thanks

Why would the domelight delay set the alarm off if the auto start is used?  I don't think it will.  Here's how to check.

Sit down in the car (or leave a window open).  Shut the engine off, open the door, lock the door, and then close it....just like you normally would when you arrive someplace.  Sit still for a minute or two.  Now, insert the key and start the engine.  Did the domelight come on at all?  If not, there's nothing to worry about.

What color is the wire at the domelight?  TechSoft calls for a BLACK/ light blue, positive trigger, in either kick panel.  Find this wire and see if it reads the delay.

It wouldn't be hard to use your four individual door triggers to operate a relay that would trigger the alarm, but there's one major flaw----the only setup I can think of would have the relay latched on all night, killing your battery----that's not going work.  Does the trigger show absolutely nothing when the door is open, or does it possibly show a slight positive voltage?  If so, it might be just enough to trigger the alarm using its purple positive trigger input, but you'll have to try to find out.

There is something different about the 2000 and and up Ford trucks and some cars now, that is a little more involved than just tapping in and using diodes to isolate, that will not work, because the GEM module actually checks the door switches to make sure they are still connected or something, I still haven't figured out why exactly, but it sends out a pulse that will false the alarm every 30 minutes or so.

Unfortunatly I don't have my notes with me on it, they are at work, I'll try and remember on Monday to grab them.

Yes there is someting different.....

thanks Chris, yes the dome light wire is BLACK/ lt blue and yes it does have the delay. The switches at the doors show no voltage just ground when closed so I can't use the 12+ trigger. The idea you mention about the relay latched when the system is armed is all I can come up with too....was hoping someone knew how to get around this.

I have everything installed and working on my truck except the auto start (hope to finish this week). I am trying to fix this problem not only for myself, but I know others that have the same problem. Same truck same alarm sets off the alarm after it autostarts and the dome light comes on.

Raven, if you find anything on this please post.......thanks