I have started having a problem with the factory alarm sounding for no reason sometimes in the middle of the night. It might take several hours or go off in an hour, no pattern. It does not make any differnce if you lock it with the door lock switch or use the key fob. I have checked the door switches and do not seen any problems. I do not suspect anyone tampering wth the vehicle. I have a couple of questions for anyone that can help:

1- Has anyone had this problem and if so what did you find?

2- How or can the system be disabled? Where is the control box located? The manuals touch on the system but do not go into details.

Vehicle is a 98 F-150 Extended cab.

Any help is appreciated

 

you have alot of aftermarket stuff on your truck? stereo equip etc..

if so chances are someone is bumping you system thinking you will shut it off out of annoyance. its a good trick thieves play on others.

unless you see it go off and noone but you is around be suspect.

additionally, if someone else near you has a similar truck or alarm it is possible, however unlikely their fob may be setting it off. and oddly enough i installed a wireless door chime in my house and my key fob for the alarm on my tiburon set it off. strange stuff happens :/

 

Im not sure if this would have any connection to your problem. But I had a aftermarket alarm installed and it would go off for no reason at all. I had to take it back to the alarm place and they installed a relay. That fixed the problem. Im not sure how factory alarms work, if it has a relay, maybe it could be faulty?

 

I have owned my 98 scab for 3 years, and the factory alarm has gone off by itself 5 or 6 times for no apparent reason. It has happened in the woods, at the grocery store, at home, at work, and no one is around when it does. I think it is radio frequencies from cell phones, microwaves, you name it. Never did figure it out. Hasn't happened in 2 months but I'm going to get a new battery shortly, maybe that will stop it.

 

Don't think anyone is "bumping" the truck as the alarm has sounded at home, at the store and at work. At work I know for a fact that no one touched it. I suspect the module or a door lock but was wondering if anyone has found this to be the culprit. Where is the module located? I can't find any info in the aftermarket manuals I have. I would pull the horn wire from the connector if I knew which one it was, the manuals don't give much info on that. Frustrated.

 

Some Ford vehicles require that a relay be put in along with some resistors to isolate a signal that is sent from the PATS module to the door pins or trunk pins, that signal is to verify that all pins are closed. However hogrider mentioned his FACTORY alarm is going off. I could think of 2 things that can cause your factory alarm to go off:

1) Your doorpins need a good oiling..Look at the sticky at the top of this forum. Your doorpins could be reading that the door is open intermittedly after you arm your factory alarm, so it goes off.

2) Your PATS module (factory alarm module) is going out.

I've seen some people completely disarm their factory alarm by grounding the "factory arm" wire off the PATS module so that it won't arm at all. I believe that it is a purple wire, I would have to check. 1st try the good ol' WD-40 deal! Good luck! lemme know

...BTW newer alarm systems utilize "codehopping" which means that each time the unit arms it uses a different "code" to arm, that way thieves can't simply tap into a code to disarm the alarm, so doorchimes shouldn't be activated..at least with newer units!

 

The ford factory units do not code hop.

You mean grnd the disarm wire... Therefore its in constant disarm. (-)

My guess is Doorpins...

 

that's what I meant ... actually with both of 'em... I think I should sleep!
I did mean that AFTERMARKET alarms codehop and yeah grounding the DISARM wire

 

The only aftermarket equipment I have is a starter cutout which has been installed since new with no problems. I will try lubricating the door pins and see what happens. For now I am removing the horn relay until I figure this out so my neighbors don't come looking for me when it goes off. If you know where the RAP module is located would be a great help. Called the local Ford dealer and they can't even give me a part number, the service guys want me to pay them to look at it. Seems Ford is really secreative about this system. Thanks for the info.

 

The factory disarm is dark green/purple above the parking brake in the driver's kick....IF you wanna ground that permanently... I would get an aftermarket alarm put in and talk to the installer about Slam-Lock on your ford and putting in a relay to stop that from being a nuisance

 

I lubricated the door locks/latches and checked the operation of the door ajar switches. Don't see anyproblems. Will see how it does. Thanks for the information.