The Ford Bronco is a handsome SUV known for its off-road prowess.
Despite its toughness alarm issues can occur.
If your Bronco’s alarm keeps going off, this article has some possible fixes.
Table of Contents
Why Does My Ford Bronco Alarm Keep Going Off?
A Ford Bronco alarm is usually triggered by a faulty hood switch or door switch as these sensors are prone to wear and tear. Other common causes include 12V battery issues, accidentally triggering the panic alarm on the key fob and key fob issues.
1. Faulty Hood Switch
A faulty hood switch is a very common cause of unwanted alarms on the Ford Bronco.
The switch is typically embedded in the hood latch.
The small electronic device is designed to detect whether the hood is open or shut and is an important part of the car’s alarm system – if it is broken, loose, wonky or dirty it can send false readings to the car’s computer thus triggering the alarm.
- Pop the hood and locate the hood switch.
- Check for any obvious damage, rust or loose connections.
- Give the hood switch a clean too (use contact cleaner), as dirt and grime can cause issues.
- You can test the switch with a continuity tester.
If you are well-versed mechanically, you can buy a new hood switch online and replace it yourself. Otherwise, we’d advise visiting your local mechanic.
Owners had this to say on Bronco6G.com:
“Dealer is replacing my hood latch under warranty. Backorder for the latch though.”
“We’ve randomly been getting “hood open” alarms every few weeks since picking up our 2023 badlands 2 Dr lux squatch last December. It’s always been while parked in the driveway except one time at the store but I parked way away from everyone.”
We found this post on TheBroncoNation.com:
“The hood sensor is a little wonky. Some folks have screwed in the hood stops about a quarter-turn and it stopped this issue.
I had the hood sensor go randomly on mine, and I gave it a good close, followed by a couple of pushes in the center (the sensor is in the latch). That did the trick for me…”
Over at BroncoSportForum, one owner had this to say:
“My 2022 Bronco Sport Big Bend is currently doing the same thing. I bought it 2 weeks ago with 8 miles on it. It’s currently in the shop to have the hood latch fixed but I’m worried from reading this that this won’t fix the issue. The alarm has been going off at 12am, 3am, 5am and is waking me and my neighbors early in the morning. It’s been very frustrating…”
One owner on the r/FordBronco subreddit shared this:
“It’s a design flaw. The switch is connected to the hood latch, Ford excessively greases the hood latch during manufacturing. The excess greases gets on the electrical contact of the switch and breaks the circuit. I cleaned the grease off mine and it solved the problem.”
2. Malfunctioning Door Switches
Faulty door switches (including the rear hatch) are another common cause of random alarms on the Bronco, similar to the hood switch, these switches monitor the open/closed status of the door – if damaged, faulty or dirty they can send false readings thereby triggering the alarm.
Door switches are a common point of failure as they are subject to wear and tear due to the doors being continually opened/closed/slammed etc.
The door latches and door switches can get dirty too which can cause issues, so the first thing you should do is give all door latches a good clean and spray some WD-40 on the latch and work it in to see if that helps.
Also check the wiring leading from the body into the door for any signs of damage, it should be in a flexible hose on the hinge side of the door.
If you suspect the alarm issues are linked to the door switch, ask your dealer to run a diagnostic test to try and pinpoint the fault.
One owner had this to say on FullSizeBronco.com:
“There is a switch on the key for each door. If it broke off, or otherwise messed up it could cause it… They are attached to the base of the key cylinder in the door. When you turn the key it disables the alarm.”
Related: Ford Bronco in Snow & Winter Driving? (Explained)
3. Accidentally Triggering the Key Fob’s Panic Button
It is not uncommon for owners to unintentionally activate the panic alarm of the Bronco.
While a lot of owners have chalked it up to poor key fob design, a few others have attributed unintentional triggering to other objects in the same pocket as the key fob.
An easy fix for this is to have a dedicated pocket for your key fob, free from any other objects (such as pens or house keys).
Over at Bronco6G.com, we found this:
“For the first week I had my new full size Bronco 2 Door Big Bend, I set the panic alarm off at least 3 times a day. Every time was due to the panic button on my fob getting pressed in my pocket. It was really driving me a little crazy, not to mention my neighbors…”
We also saw this comment on TheBroncoNation.com:
“The key fob is easy to hit if it’s in your pocket. i’ve set mine off probably 15 times since february, never accidently set off a car alarm from key fob before, but with this one its every week or two I’ll do it”
One owner shared his experience on the r/Bronco subreddit:
“I’m convinced all my neighbors hate me because I accidentally set my car alarm off on my Bronco several times a day just from sitting on my keys in my pocket…”
4. Key Fob Running on Low Battery
A common cause of mysterious alarms on the Bronco is a low key fob battery. Similarly, if the fob is dirty or dusty this can also cause alarm issues.
Give the inside of your fob a clean and replace the battery to eliminate this possible cause. It’s worth spending a bit extra for a good brand of battery.
- To open your key fob, stick your prying tool into the slit or gap between the two halves of the outer casing and gently apply upward pressure to pop open the device.
- Remove the battery.
- Give the key fob a good clean to remove any dirt or fluff – a cotton swab and some rubbing alcohol should do the trick.
- Check for damage, rust or loose connection (you may need a new key fob depending on what you find).
- Be sure to insert the new battery facing the right way up.
- Assemble the outer casing of your key fob by clamping them back together.
On BroncoZone.com, one owner found the solution as stated below:
“I replaced the batteries and got it to stop…”
5. Faulty Key Fob
Another reported cause of nuisance alarms on the Bronco is a faulty key fob.
If you have 2 remotes, try taking the battery out of one and use the other for a while.
If the alarm problems persist, and you have tried cleaning the inside of the fob(s) and changing the battery, the best thing to do is speak with your dealer.
6. Drained 12V Battery
A faulty or weakened car battery causes a variety of problems, including accidentally triggering the Bronco alarm.
The best thing to do is take your Bronco for a battery health check, these are usually quite inexpensive or sometimes free such as at AutoZone.
Or you can test it yourself with a multimeter (see the guide at the end of this article).
A healthy 12V battery should be about 12.6 to 12.8 volts while a weakened battery reads below 12 volts.
7. Loose or Bad 12V Battery Connections
Loose or bad 12V battery connections can cause a number of problems, including triggering the alarm of your Bronco.
A bad connection can be caused by dirt or gunk buildup.
The terminals may have come loose from driving and vibrations etc.
Make sure the engine is off before doing any work on the battery.
- Inspect the battery and look for any signs of damage, dirt build-up, rust, or corrosion.
- Disconnect the battery and loosen the nuts on the clamps using a wrench.
- Remove the negative clamp, marked with a “-” first.
- Clean the terminals with a toothbrush dipped in a mix of baking soda and water, rinse with distilled water and dry with a cloth.
Reconnect the battery, ensuring tight connections.
One owner on Bronco6G.com had this to say:
“Check if battery terminals are tight and all fuses seated.”
8. Not Closing Doors, Hood, or Trunk Properly
Something as simple as not properly closing the doors, hood, or trunk will inevitably trigger the alarm.
Make sure to check if you have closed every point of entry of your vehicle to avoid accidentally tripping your Bronco’s alarm.
This suggestion on TheBroncoNation.com may help:
“Try opening your hood and then let it slam closed. If that doesn’t work then maybe adjust (lower) your hood height using the twist top adjusters on left/right with the hood open.”
We found this relevant post on the r/Ford subreddit:
“The perimeter alarm sets when you lock the doors with the remote. If an interior door is opened without pressing unlock, it will set off the horn…”
9. Incorrectly Installed Aftermarket Alarm
An incorrectly installed or faulty aftermarket alarm system is a common cause of nuisance alarms.
Aftermarket alarms are typically far more complex than any factory-installed equipment which makes them more prone to issues.
They may also have been installed by incompetent individuals.
If you are experiencing issues with an aftermarket alarm, the best thing to do is speak with a reputable auto electrician.
One owner posted this comment on FullSizeBronco.com:
“OP, your alarm must be aftermarket, which means it could be acting up for any number of reasons. You’ll have to get a manual for your specific model or remove it completely. If it’s an off brand I’d say there’s a good chance it’s failed.”
10. Wind and Vibration
The Ford Bronco’s alarm sensors are quite sensitive. Excessive wind or vibration can trip the alarm quite easily, according to reports online.
To deal with the wind, make sure all doors and windows are shut tight.
As for the vibration, keep your Bronco away from roads or highways when parked.
11. Water Leakage
Water leaking into the latches and sensors is quite common for owners of the Bronco. It is essentially a design flaw that can trigger the vehicle’s alarm.
While the quick fix is to wipe down vulnerable areas around your latches and switches, it would be much better to consult with auto mechanics to find a long-term solution (such as adding additional seals or rubber linings).
12. Rust and Corrosion on Door and Hood Latches
Rust and corrosion can also damage the latches and switches, which may trick the sensors into detecting that a door or the front hood is open.
If your car is frequently exposed to moisture or other external elements, then you should routinely inspect critical areas of your vehicle for any sign of rust or corrosion.
13. Damaged Wiring
Damaged electrical wiring can cause a wide range of problems, it can often be tricky to pinpoint too and you may need to have an auto electrician run some diagnostic tests.
14. Animals Climbing On The Vehicle
If your alarm has been set off in the middle of the night, it may have been by an animal climbing on the car.
States such as Illinois, Indiana, Iowa, Texas, Wisconsin, and Carolina have large wild raccoon populations.
Have a look for footprints on the hood and the roof.
If you have a CCTV system, examine the footage. These animals usually appear during the night.
Alternative Suggestions
Check for Recalls or TSBs
By entering your car’s VIN number on Ford’s recall page or the NTHSA’s Safety Issues & Recalls page you can determine whether or not there is a TSB or recall for your vehicle and if there is you’ll want to get it addressed.
A recall is issued by a vehicle manufacturer for issues that are safety-related, while a TSB covers components that may be malfunctioning but don’t compromise the safety of the vehicle.
Disconnect the Battery
Sometimes mysterious alarm problems can disappear with a simple reboot, there are no guarantees here but it’s worth a try.
Disconnect the battery for 20 seconds and this resets many of the electronics in the vehicle.
Check For Warning Messages
When the alarm occurs can you see any lights or warning messages on the instrument panel?
This can give a clue as to what’s causing the alarm e.g. ‘Hood Ajar’.
Take it to a Ford Dealership
If needed, take your Ford to the dealership.
Tell them you are NOT paying for a check on what the problem might be.
Ask them if they will check it for free.
Most dealerships and other places do quick/initial diagnosis for no money as they plan to make money for the repair of your vehicle.
If your unit is still under warranty then they should fix and resolve the issue for free.
How to Test the 12V Battery
How to Test the Battery:
- Before testing, remove the surface charge from the battery, this allows for an accurate reading.
- Simply turn on the headlights for 2 minutes then turn off.
- Set the multimeter dial to the ’20 Volts’ setting.
- Make sure the car is turned OFF.
The multimeter will have a red probe and a black probe.
- The red probe is for making contact with the positive terminal.
- The black probe is for making contact with the negative terminal.
Measure across the battery terminals.
- The meter should display a reading, if the battery is fully charged the voltage should be between 12.2 and 12.6 volts.
- Anything under 12V and the battery should be charged or replaced.
Sources
https://www.ford.com/support/owner-manuals/