Factory Alarm Going Off for No Reason

:dunno:My 2005 Lincoln LS is developing a very bad and noisy habit. From time to time after I park the car and lock it with the remote key fob, a few minutes later, the factory alarm goes off-horns blowing and lights flashing. It will sound for about a minute and stop. A few minutes later it will start all over again. It will keep this up until I unlock the car. It is intermitent. More often than not ,everything is fine. I can lock the car and not have the alarm go off. Unfortuately, this has been happening more and more frequently in the past week or so. So to prevent the alarm from sounding, I have been leaving the car unlocked. I hate having to do that.

Background-I seems to have started when I had the dealer replace the heater control unit under the hood. The heater came on and would not go back to A/C. It now works perfectly. I don't know this is related, but thought this info might help.

Any thoughts? This is the only issue I am having. :confused:

Your help and suggestions will be greatly appreciated.

It would have been the DCCV that was replaced.
I'd check the adjustment of the hood and the hood open alarm switch. Maybe even just disconnect it to see if it is the problem. (It looks just like the trunk ajar switch does.)

Thank you! That's exactly what was replaced. I could not remember the name of it. I am better at old cars-simple, easy(most of the time).

Anyway, at the risk of sounding like a complete moron, where is the hood alarm switch located? And where is the trunk alarm switch located. I may have bumped or bent it over the holidays. I did a number of trips packing and unpacking the trunk and may have inadvertantly damaged it.

Once I locate it, how do I disconnect it? Once disconnected, will anything else be affected?

Thanks for taking your time to respond I do appreciate this information very much.:1zhelp:

I took a picture of it for you, but it won't let me upload it here.
It's on the driver's side, just behind the air filter box. It is black and pointed up towards the hood. It's kind of like a rubber Christmas tree. Press down on it, and you will see that it is a switch plunger. I haven't really looked into it, but I am sure that the wiring to it is easy to unplug.

In general, the alarm would be going off because it thinks that a door, trunk, or the hood has been opened. Since you don't mention getting any false door or trunk ajar warnings while you are driving, I wonder if it might be the hood switch.
Of course, it could be an issue with a failing FEM or REM, or wiring.

I am going to check it out in the morning.
It waould make sense. I had the dealer change the air filter at the time that they replaced the DCCV.

One more question, if you don't mind-REM FEM- What and where are these?


Thank you:smile:

I am going to check it out in the morning.
It waould make sense. I had the dealer change the air filter at the time that they replaced the DCCV.

One more question, if you don't mind-REM FEM- What and where are these?


Thank you:smile:

REM = Rear Electronic Module. It's in the trunk on the right side behind the trunk light and trim.
FEM = Front Electronics Module. It's under the dash.

Thank You Very Much for all of your help and information.