Car alarm going off randomly

[ksurfer2]

This happened again last night and for some reason, it only seems to happen in the wee hours of the morning. The alarm on my 2019 F250 will go off randomly. I say random, but there is one thing in common. It only happens when there are temperature changes or it gets cold out. Since I live in Florida, cold is relative. Last night it was in the 50's here, which is a welcome change from the overnight lows in the 70/80's we have had for the past 6 months. At 3am, my truck alarm went off. I went outside and turned it off, checked around and no signs of mischief. I live in the middle of nowhere, so there are not many people around and fewer looking for trouble. This happened a couple of times last winter as well. I did a quick search about random car alarm activations and found the following:

6. By temperature changes​

The alarm might be triggered by temperature changes. If it’s too cold outside or inside your Ford F250, the sensors might think there’s something wrong and start triggering the alarm.

Open some windows to get the temperature balanced and then reset the alarm.

Has anyone ever heard of this? Any suggestions on how to keep it from happening? I ( and my neighbors) would appreciate any solutions.

 

[Ron H]

Maybe not your hassle, but had a problem with this on our sedan after getting it back from the body shop (hit a deer needing new fender and hood). Also searching reviews on this, it wasn’t an uncommon problem for our car anyway. A hood sensor out of adjustment. Adjusted it and haven’t had any issue since.

 

[cr8crshr]

Just disable it and make sure to lock it up at night if you do not park it in say a garage. I actually wonder if they are even necessary at all as they do tend to have a mind of their own...cr8crshr/Bill

 

[5.7 hemi]

Batteries, have them load check individually.

 

[khryslerkid]

Just disable it and make sure to lock it up at night if you do not park it in say a garage. I actually wonder if they are even necessary at all as they do tend to have a mind of their own...cr8crshr/Bill

And nobody pays any mind to them anyway.

 

[fourgearsavoy]

Usually the hood latch switch is the culprit when the alarm goes off all by itself.

Gus

 

[eldubb440]

illegals looking for a place to crash

 

[moparwacko]

It's a Ford, who would want to steal it?




Try a key fob battery. That was the culprit on our 2022 Ram. It had something to do with "fob proximity sensing". One of the Fobs had a battery issue. Ram dealer replaced both batteries, and re-flashed the truck. It hasn't happened since.
Good luck.

 

[Basket case]

leave it at Wallmart, no one will notice

 

[WileERobby]

My washing machine goes on randomly. It's the cheap chinese electronics in these gadgets nowadays.

 

[eldubb440]

fobs...... another reason not to own late model

 

[5.7 hemi]

Guess the OP isn’t all that concerned since there hasn’t been any replies.

 

[ksurfer2]

Guess the OP isn’t all that concerned since there hasn’t been any replies.

Still here and still concerned. I did some more poking around on line and found a way to manually disable the alarm by turning the key in the door twice to the right. There is no audible indication that the alarm is disabled, but it didn't go off last night (also, it wasn't as cold last night)

Batteries in the truck are brand new, I replaced them a couple of weeks ago. I will try changing the battery in the FOB. It is just hard to tell what works and what doesn't because it is such a random occurrence.

 

[Dennis H]

Change both FOB batteries. Can’t hurt. Press lock and unlock simultaneously til it times out to attempt a reset. FOB batteries used to last 10 years, now more like 2-3 with all the modern nanny crap running so much. Let us know the fix.

 

[padam]

This is the best place for a car alarm.

 

[YY1]

Maybe your truck is pining for the 1990's when everyone got routinely awakened at 2:00 am because the same car alarm that went off the night before, and three times last week, went off again, and the owner couldn't be bothered (or had the TV and AC on) to come out and shut it off untill it timed out after 20 minutes.

I bet every neighborhood had "that guy" and I bet you can all still hear the cycle of different alarm sounds.

 

[eldubb440]

car alarms are like crying wolf....... no one pays them attention any more

 

[Bobzilla]

This happened again last night and for some reason, it only seems to happen in the wee hours of the morning. The alarm on my 2019 F250 will go off randomly. I say random, but there is one thing in common. It only happens when there are temperature changes or it gets cold out. Since I live in Florida, cold is relative. Last night it was in the 50's here, which is a welcome change from the overnight lows in the 70/80's we have had for the past 6 months. At 3am, my truck alarm went off. I went outside and turned it off, checked around and no signs of mischief. I live in the middle of nowhere, so there are not many people around and fewer looking for trouble. This happened a couple of times last winter as well. I did a quick search about random car alarm activations and found the following:

6. By temperature changes​

The alarm might be triggered by temperature changes. If it’s too cold outside or inside your Ford F250, the sensors might think there’s something wrong and start triggering the alarm.

Open some windows to get the temperature balanced and then reset the alarm.

Has anyone ever heard of this? Any suggestions on how to keep it from happening? I ( and my neighbors) would appreciate any solutions.

I assume this is a factory alarm system. I will also assume there is no aftermarket equipment causing this, and no battery issues as already mentioned.

First, identify anything that will trigger the alarm under normal situations, such as door switches and the hood switch that was already mentioned. Some vehicles have locking tailgate latch so it may have a switch in there as well. Not sure if the F250 would have it, but some vehicles are even equipped with a glass breakage sensor integrated into the rear glass defogger grid.

Once identified, start checking the easiest ones first. Check door, hood, and tailgate adjustments. If there is any body damage that could contribute to false activation if the switches are not indicating the closed position properly. If nothing is damaged or out of adjustment, start unplugging the switches and checking the connectors for corrosion. Corrosion can be affected my temperature too. We used to see this all the time on S10 Blazers. The rear liftgate glass release switch would get water in it, start to corrode, and then the alarm would sound during the night when the temperature cooled, although these sometimes caused a battery drain with no alarm sounding for the same reason.

A dealer scan tool can usually monitor the door and hood switch inputs so they can see if any are reading incorrectly even when the alarm is not sounding, although it can still be one of those switches even if it does not show up on the scan tool at the time it is checked when problem is not happening.

If all else fails, disconnect one switch and evaluate it. If the alarm sounds again at some point, that switch cannot be the cause. This takes time for sure, but not much else can be done unless the problem gets so bad it is happening all the time.

 

[dart4forte]

It's a Ford, who would want to steal it?




Try a key fob battery. That was the culprit on our 2022 Ram. It had something to do with "fob proximity sensing". One of the Fobs had a battery issue. Ram dealer replaced both batteries, and re-flashed the truck. It hasn't happened since.
Good luck.

Agree