Erratic Anti-Theft Alarm

[BearCave]

Hi Everyone!

I am new to this forum as well as being a recent first- time Ford owner. A few weeks ago I bought a 1997 Ford Explorer XLT with low miles/excellent shape. After the first few days of owning it, the anti-theft alarm on it is going crazy!

The problem is that about five to ten minutes (it doesn't happen right away) after the vehicle is parked and cooling down from being driven and the anti-theft system is enabled (either by remote fob, keypad, or just locking the doors with the power lock button on the door panel, it doesn't matter) the alarm will just start going off for no apparent reason! Why is this? Could it be a bad door jamb sensor? Is there a bad relay of some sorts? I then disarm it, and after the vehicle has had a chance to cool down (a half hour or so) I can re-arm it and it's fine and never goes off again! It's really starting to drive me AND my neighbors nuts! I can't even lock my vehicle now, for fear that the alarm will go off after five to ten minutes!!

Thank you for any advice or tips that anyone can offer!

I really love this truck otherwise!!

 

[EBInterceptor]

I'm not sure what it means if it's going off consistently like that, but on my old X, my alarm system would react with other people setting their alarms or unlocking their doors and what not. I even had people setting off my alarm for fun... Maybe something wrong with your computer module? I'm not really sure about this one.

 

[dreamr]

My VW with factory alrm system had this same problem. After much fiddling i fimally took it to the dealer and had the little button sensor thing in the driver door jam replaced

 

[BearCave]

I did fail to mention that when I first bought it, the interior lights did not come on when I would open the driver-side door. I read up on some forums about this, because this particular year ('97) doesn't have the traditional door jamb "buttons". The door jamb indicators are actually mounted inside the door somehow with the door latches. I sprayed the latches with WD-40 and worked them (opening and closing the door), and now the interior lights as well as the "door ajar" light (when the truck is running) come on all the time. So that fixed that problem.

Could the door jamb indicator be relative to this problem? Could it be shorting out somehow? I just find it odd because it only happens while the truck is still warm.

Thanks again!

 

[X~FACTOR]

Originally posted by BearCave
The problem is that about five to ten minutes (it doesn't happen right away) after the vehicle is parked and cooling down from being driven and the anti-theft system is enabled the alarm will just start going off for no apparent reason!

This is caused by the drop of the temperature inside the cabin. Some car alarms has this sensor built in. It is set too sensative. Bring it back to who installed it and explain your problem and they should direct you to the right sensor.

 

[BearCave]

Is this a setting that's adjustable on the factory anti-theft systems? Because that is the only system on the truck, it isn't an aftermarket alarm.

 

[EBInterceptor]

Sounds like you're on the right track. If the interior lights and the door ajar light comes on when you're driving then it definately could be the sensor being bad. If it senses that the door is open then it will trigger your alarm, as it does when you're driving and turns on the lights. Also I'm assuming that it is a Ford factory alarm.

 

[BearCave]

It wasn't that the lights were coming on while I was driving, it was that they wouldn't come on whenever I opened the driver door (like saying that the door was still shut). Ever since I used WD-40 on the latch, that seems to have fixed the problem because they do come on every time I open the door now.

I'm kind of suspecting that there may still be a problem with the door jamb sensor, but it doesn't explain why it only happens about five to ten minutes after the truck has been driven and never any other time.

This is turning out to be a pretty weird problem!

 

[X~FACTOR]

I had the very same problem when I put in my new Alarm (aftermarket) system. It was a sensor that's causing the alarm to go off. Factory alarm system normally do not have one of these sensors but you never know you might have a better Alarm system than normal.

 

[97xlt4x4]

If it is a ford factory alarm, there should also be a "plunger" under the hood to detect someone getting in there. It should be near the air filter sticking up to make contact with the hood when it's closed. I would check that since you say it only does it when the engine is warm.