• SHOP
  • CLUB
0
My Garage
Add vehicle
0
items #83-3256
£ 0,00
Your basket is empty

Why your car alarm keeps going off and how to stop it

Table of content

  1. Does my car have a factory-fitted alarm and immobiliser?
  2. Why does my car alarm keep going off?
  3. Car alarm randomly goes off at night
  4. What causes the car alarm to go off?
  5. How long do car alarms go off for
  6. How to stop my car alarm from randomly going off

A properly functioning car alarm is essential for protecting your vehicle from theft and ensuring your peace of mind. However, if your car alarm keeps going off unexpectedly, it can be more than just an annoyance; it can signal underlying issues that need attention. Learn more about the potential causes of car alarm malfunctions and how to solve them below.

Does my car have a factory-fitted alarm and immobiliser?

If you’re unsure whether your car has both an anti-theft alarm and an immobiliser, you can consult the car owner’s manual or check yourself by trying to open one of the car doors after it has been locked. A mechanic can also take a look if you’re still uncertain. Generally speaking, if your car was made after October 1998, it should have its own immobiliser as well as a car alarm system.

how to stop my car alarm from randomly going off

All keyless cars will have some sort of immobiliser as this is required to prevent unauthorised use of the car. The alarm and immobiliser should deactivate when the vehicle receives a signal from the key fob chip when it is nearby or when the driver presses the fob buttons. Find out more about the types of anti-theft systems and how they work in this blog.

Why does my car alarm keep going off?

If your car alarm keeps going off for no apparent reason, it is most likely due to some kind of electrical fault. For example, it could be due to faulty sensors or wiring that cause the system to detect false threats. Sometimes it happens because the car battery is running low or is flat, or due to a blown fuse. Thankfully, faulty ones are quickly diagnosed, easy to replace and pick up new car fuses. The alarm can also be triggered due to electrical interferences, temperature changes, and extreme weather.

-54%
S90 HELLA 3AM 922 000-971 Air Horn
Reviews - 12
Parts Details
  • Voltage [V]: 12
  • Power Consumption [W]: 42
  • Sound Level [dB(A)]: 111
  • Frequency Range [Hz]: 350, 415
  • Power consumption [A]: 3,5
  • Protection Type (IP Code): IP65
  • fulfils ECE norm: R28
  • Registration Type: ECE approved
  • Signal: High Tone, Low Tone
  • Housing Colour: red / black
  • Quantity: 2
  • Operating Mode: Electric
  • Diameter [mm]: 90
  • Temperature range from [°C]: -40
  • Temperature range to [°C]: 90
  • Mounting Type: Flat Plug-in Connector
  • Supplementary Article / Supplementary Info Info 2: with E quality seal
  • Assy. / disassy. by qualified personnel required!
  • HELLA: Air Horn
  • Item number: 3AM 922 000-971
  • Our price: £ 9,67
  • Condition: New
Details
HELLA Air Horn
Article number: 3AM 922 000-971
compared to RRP £ 21,23

£ 9,67
price incl. 20% VAT, excl. delivery costs
BH-RS-N BOSCH 9 320 335 007 Horn 12V, 510 Hz, 110 dB(A), Electric-pneumatic, 80W, 80 mm, Holder may need adaptation
Reviews - 8
Parts Details
  • Quantity Unit: Kit
  • Operating Mode: Electric-pneumatic
  • Voltage [V]: 12
  • Power Consumption [W]: 80
  • Frequency Range [Hz]: 510
  • Sound Level [dB(A)]: 110
  • Width [mm]: 85
  • Diameter [mm]: 80
  • Number of connectors: 2
  • Supplementary Article / Supplementary Info Info 2: Holder may need adaptation
  • Connector / Clamp: Connector may need adjustment
  • BOSCH: Horn
  • Item number: 9 320 335 007
  • Our price: £ 20,45
  • Condition: New
Details
BOSCH Horn 12V, 510 Hz, 110 dB(A), Electric-pneumatic, 80W, 80 mm, Holder may need adaptation
Article number: 9 320 335 007
£ 20,45
price incl. 20% VAT, excl. delivery costs
DPA 89370158602 Fuse Box
Reviews - 5
Parts Details
  • DPA: Fuse Box
  • Item number: 89370158602
  • Our price: £ 17,48
  • Condition: New
Details
DPA Fuse Box
Article number: 89370158602
£ 17,48
price incl. 20% VAT, excl. delivery costs
BOSCH 0 986 AH0 745 Horn 12V, 110 dB(A), High Tone, pneumatic, schwarz, 60W
Reviews - 3
Parts Details
  • Bore Diameter [mm]: 8,3
  • Operating Mode: pneumatic
  • Voltage [V]: 12
  • Power Consumption [W]: 60
  • Signal: High Tone
  • Sound Level [dB(A)]: 110
  • Specification: schwarz
  • BOSCH: Horn
  • Item number: 0 986 AH0 745
  • Our price: £ 9,56
  • Condition: New
Details
BOSCH Horn 12V, 110 dB(A), High Tone, pneumatic, schwarz, 60W
Article number: 0 986 AH0 745
£ 9,56
price incl. 20% VAT, excl. delivery costs
-35%
D 239 HELLA 8JS 728 596-322 Fuse blue, 58V
Reviews - 1
Parts Details
  • Fuse Type: Low profile mini blade fuse
  • Voltage to [V]: 58
  • Width [mm]: 10,9
  • Depth [mm]: 3,8
  • Height [mm]: 8,4
  • DIN / ISO: 8820-9
  • Colour: blue
  • Packing Type: Blister Pack
  • Temperature range from [°C]: -40
  • Temperature range to [°C]: +125
  • Contact surface: Zinc-coated
  • Housing material: PA (polyamide)
  • Assy. / disassy. by qualified personnel required!
  • HELLA: Fuse
  • Item number: 8JS 728 596-322
  • Condition: New
Details
HELLA Fuse blue, 58V
Article number: 8JS 728 596-322
compared to RRP £ 3,25

£ 2,09
Price per item
price incl. 20% VAT, excl. delivery costs

Car alarm randomly goes off at night

In addition to common electrical faults, such as a low battery, loose connections and bad sensors, car alarms often go off at night as a result of extreme weather or the environment. For example, when there is heavy wind, rain, or thunderstorms, the alarm can be set off or if there are strong vibrations due to heavy traffic and flows of pedestrians.

However, you should also check to make sure that there are definitely no signs of a potential break in or animal activity as this is a time when both thieves and animal invaders are most active.

car alarm keeps going off

What causes the car alarm to go off?

Common causes that trigger the alarm:

  • Faulty or sensitive alarm system – the sensors can go off by themselves if there is a false signal or due to something as small as a heavy gust of wind, parking on an uneven surface, or a small animal brushing against the car.
  • Wiring problems – damaged or frayed wires in the alarm system can create short circuits or inconsistent signals, which can lead to the alarm going off unexpectedly
  • Battery faults – a weak or dying car battery can cause fluctuations in the voltage, which might confuse the alarm system into thinking there’s a security breach. In the event of a fault, you should pick up a new car battery.
  • Key fob malfunctions – electronic devices or signals from nearby sources can interfere with the key fob’s signal, potentially causing the alarm to go off.
  • Environmental and weather conditions – Thunderstorms, heavy rain, and strong winds can all cause vibrations or disturbances that trigger the alarm.
  • Animals – windows that are left open, particularly overnight, may allow creatures to gain entry. Some rodents are attracted to the smell of fuel or the car’s warmth.
  • Faulty horns – Some may mistake a faulty horn for their alarm. If the horn relay goes bad or the parts are worn, for example, it may go off spontaneously or continuously. If this happens, make sure to install a new car horn unit.

WINDTONE, 12V LOW, BLA BOSCH 0 986 AH0 501 Horn 12V, 110 dB(A), Electric-pneumatic, 60W, Holder may need adaptation
Reviews - 4
Parts Details
  • Length [mm]: 92
  • Bore Diameter [mm]: 8,7
  • Operating Mode: Electric-pneumatic
  • Voltage [V]: 12
  • Power Consumption [W]: 60
  • Sound Level [dB(A)]: 110
  • Width [mm]: 57
  • Height [mm]: 123,6
  • Supplementary Article / Supplementary Info Info 2: Holder may need adaptation
  • Connector / Clamp: Connector may need adjustment
  • BOSCH: Horn
  • Item number: 0 986 AH0 501
  • Our price: £ 11,00
  • Condition: New
Details
BOSCH Horn 12V, 110 dB(A), Electric-pneumatic, 60W, Holder may need adaptation
Article number: 0 986 AH0 501
£ 11,00
price incl. 20% VAT, excl. delivery costs
-68%
102 955 001 TOPRAN 102 955 Air Horn with fastening material
Reviews - 9
Parts Details
  • Signal Horn: Signal Horn
  • Operating Mode: Electric
  • Number of pins: 2
  • Signal: Low Tone
  • Frequency Range [Hz]: 420
  • Connector Shape: rectangular
  • Supplementary Article / Supplementary Info Info 2: with fastening material
  • Operating voltage [V]: 12
  • TOPRAN: Air Horn
  • Item number: 102 955
  • Our price: £ 6,89
  • Condition: New
Details
TOPRAN Air Horn with fastening material
Article number: 102 955
compared to RRP £ 21,67

£ 6,89
price incl. 20% VAT, excl. delivery costs
-28%
D 109 HELLA 8JS 740 026-221 Fuse 80A, black, 32V
Reviews - 1
Parts Details
  • Fuse Type: PAL block fuse, Series2
  • Current Strength [A]: 80
  • Voltage to [V]: 32
  • Width [mm]: 22,4
  • Depth [mm]: 22,4
  • Height [mm]: 45,5
  • DIN / ISO: JASO 0612
  • Colour: black
  • Packing Type: Blister Pack
  • Temperature range from [°C]: -40
  • Temperature range to [°C]: +125
  • Assy. / disassy. by qualified personnel required!
  • HELLA: Fuse
  • Item number: 8JS 740 026-221
  • Condition: New
Details
HELLA Fuse 80A, black, 32V
Article number: 8JS 740 026-221
compared to RRP £ 9,40

£ 6,68
Price per item
price incl. 20% VAT, excl. delivery costs
-24%
D 227 HELLA 8JS 740 026-731 Fuse 20A, blue, 58V
Parts Details
  • Fuse Type: for low JCASE fuse
  • Current Strength [A]: 20
  • Voltage to [V]: 58
  • Width [mm]: 12
  • Depth [mm]: 14,5
  • Height [mm]: 16
  • DIN / ISO: 8820-4
  • Colour: blue
  • Packing Type: Blister Pack
  • Temperature range from [°C]: -40
  • Temperature range to [°C]: +125
  • fulfils SAE norm: 2741
  • Assy. / disassy. by qualified personnel required!
  • HELLA: Fuse
  • Item number: 8JS 740 026-731
  • Condition: New
Details
HELLA Fuse 20A, blue, 58V
Article number: 8JS 740 026-731
compared to RRP £ 7,30

£ 5,53
Price per item
price incl. 20% VAT, excl. delivery costs
BOSCH 1 987 529 038 Fuse 5A, 32V
Parts Details
  • Voltage to [V]: 32
  • DIN / ISO: 72581 / 3
  • Current Strength [A]: 5
  • Fuse blow characteristics: F Fast Acting
  • Fuse Type: Mini-Flat Fuse
  • BOSCH: Fuse
  • Item number: 1 987 529 038
  • Condition: New
Details
BOSCH Fuse 5A, 32V
Article number: 1 987 529 038
£ 3,99
Price per set of 10 pieces
price incl. 20% VAT, excl. delivery costs

How long do car alarms go off for

Most car alarms go off for 30 seconds to several minutes. However, if your alarm goes off for 20 minutes or more, action may be taken against you as this is considered a noise nuisance in most cities.

How to stop my car alarm from randomly going off

Make sure to lock the doors using the key or fob and try turning off the alarm manually. If the alarm is going almost every day then it is most likely due to problems with the sensors or electrics.

Other tips:

  • Make sure that the windows are closed at night and the car is parked on an even surface.
  • Park the car inside a garage or away from busy traffic if possible.
  • Turn off car lights and electronic devices when not in use to maintain the car battery charge.

Top products related to this topic:

AUTODOC Bestsellers: parts at a good price

-10%
MCase HELLA 8JS 218 228-031 Fuse 25A, white
Parts Details
  • Fuse Type: MCASE fuse
  • Current Strength [A]: 25
  • Width [mm]: 9,7
  • Depth [mm]: 6,2
  • Height [mm]: 17,5
  • DIN / ISO: 8820-4
  • Colour: white
  • Packing Type: Blister Pack
  • Temperature range from [°C]: -40
  • Temperature range to [°C]: +125
  • fulfils SAE norm: 2741
  • Assy. / disassy. by qualified personnel required!
  • HELLA: Fuse
  • Item number: 8JS 218 228-031
  • Condition: New
Details
HELLA Fuse 25A, white
Article number: 8JS 218 228-031
compared to RRP £ 3,12

£ 2,80
Price per item
price incl. 20% VAT, excl. delivery costs
-28%
D 115 HELLA 8JS 740 026-271 Fuse 120A, white, 32V
Parts Details
  • Fuse Type: PAL block fuse, Series2
  • Current Strength [A]: 120
  • Voltage to [V]: 32
  • Width [mm]: 22,4
  • Depth [mm]: 22,4
  • Height [mm]: 45,5
  • DIN / ISO: JASO 0612
  • Colour: white
  • Packing Type: Blister Pack
  • Temperature range from [°C]: -40
  • Temperature range to [°C]: +125
  • Assy. / disassy. by qualified personnel required!
  • HELLA: Fuse
  • Item number: 8JS 740 026-271
  • Condition: New
Details
HELLA Fuse 120A, white, 32V
Article number: 8JS 740 026-271
compared to RRP £ 8,75

£ 6,27
Price per item
price incl. 20% VAT, excl. delivery costs
-31%
D 232 HELLA 8JS 740 026-781 Fuse 60A, yellow, 58V
Reviews - 1
Parts Details
  • Fuse Type: for low JCASE fuse
  • Current Strength [A]: 60
  • Voltage to [V]: 58
  • Width [mm]: 12
  • Depth [mm]: 14,5
  • Height [mm]: 16
  • DIN / ISO: 8820-4
  • Colour: yellow
  • Packing Type: Blister Pack
  • Temperature range from [°C]: -40
  • Temperature range to [°C]: +125
  • fulfils SAE norm: 2741
  • Assy. / disassy. by qualified personnel required!
  • HELLA: Fuse
  • Item number: 8JS 740 026-781
  • Condition: New
Details
HELLA Fuse 60A, yellow, 58V
Article number: 8JS 740 026-781
compared to RRP £ 8,09

£ 5,53
Price per item
price incl. 20% VAT, excl. delivery costs
CARPOINT Tour de France 0524731 Horn 12V, 117 dB(A), Low Tone, Middle Tone, High Tone, pneumatic
Reviews - 1
Parts Details
  • Voltage [V]: 12
  • Sound Level [dB(A)]: 117
  • Operating Mode: pneumatic
  • Signal: Low Tone, Middle Tone, High Tone
  • Product line: Tour de France
  • Fastening Type: Direct fastening
  • CARPOINT: Horn
  • Item number: 0524731
  • Our price: £ 106,91
  • Condition: New
Details
CARPOINT Horn 12V, 117 dB(A), Low Tone, Middle Tone, High Tone, pneumatic
Article number: 0524731
£ 106,91
price incl. 20% VAT, excl. delivery costs
VEMO Original Quality V10-77-0912 Air Horn
Reviews - 1
Parts Details
  • Voltage [V]: 12
  • Diameter [mm]: 100
  • Operating Mode: Electric
  • Frequency Range [Hz]: 450
  • Weight [kg]: 0,349
  • Product line: Original Quality
  • Packaging width [cm]: 8,8
  • Packaging height [cm]: 8,2
  • Packaging Depth [cm]: 14,1
  • VEMO: Air Horn
  • Item number: V10-77-0912
  • Our price: £ 12,33
  • Condition: New
Details
VEMO Air Horn
Article number: V10-77-0912
£ 12,33
price incl. 20% VAT, excl. delivery costs
-34%
D 133 HELLA 8JS 711 683-851 Fuse 40A, Orange, 32V
Reviews - 6
Parts Details
  • Fuse Type: ATO fuse
  • Current Strength [A]: 40
  • Voltage to [V]: 32
  • Width [mm]: 19,1
  • Depth [mm]: 5,1
  • Height [mm]: 18,8
  • DIN / ISO: 8820-3
  • Colour: Orange
  • Packing Type: Blister Pack
  • Temperature range from [°C]: -40
  • Temperature range to [°C]: +125
  • fulfils SAE norm: J1284
  • Contact surface: Tin-plated
  • Housing material: PA (polyamide)
  • Assy. / disassy. by qualified personnel required!
  • HELLA: Fuse
  • Item number: 8JS 711 683-851
  • Condition: New
Details
HELLA Fuse 40A, Orange, 32V
Article number: 8JS 711 683-851
compared to RRP £ 3,11

£ 2,05
Price per set of 5 pieces
price incl. 20% VAT, excl. delivery costs
-23%
D 111 HELLA 8JS 740 026-301 Fuse 80A, black, 32V
Reviews - 1
Parts Details
  • Fuse Type: PAL block fuse, Series2
  • Current Strength [A]: 80
  • Voltage to [V]: 32
  • Width [mm]: 22,8
  • Depth [mm]: 16
  • Height [mm]: 21,5
  • Bolt Distance [mm]: 49
  • DIN / ISO: 8820-4
  • Colour: black
  • Packing Type: Blister Pack
  • Temperature range from [°C]: -40
  • Temperature range to [°C]: +125
  • Assy. / disassy. by qualified personnel required!
  • HELLA: Fuse
  • Item number: 8JS 740 026-301
  • Condition: New
Details
HELLA Fuse 80A, black, 32V
Article number: 8JS 740 026-301
compared to RRP £ 7,33

£ 5,59
Price per item
price incl. 20% VAT, excl. delivery costs
BH-BT BOSCH 0 986 AH0 203 Air Horn
Reviews - 4
Parts Details
  • Width [mm]: 57
  • Bore Diameter [mm]: 8,5
  • Quantity Unit: Kit
  • Rated Voltage [V]: 12
  • Power Consumption [W]: 48
  • Operating Mode: Electric
  • Diameter [mm]: 156
  • Height [mm]: 123,6
  • Number of connectors: 2
  • Sound Level [dB(A)]: 118
  • Specification: verchromt
  • BOSCH: Air Horn
  • Item number: 0 986 AH0 203
  • Our price: £ 39,04
  • Condition: New
Details
BOSCH Air Horn
Article number: 0 986 AH0 203
£ 39,04
price incl. 20% VAT, excl. delivery costs
BOSCH 1 904 520 018 Fuse 16A, 32V
Reviews - 10
Parts Details
  • Voltage to [V]: 32
  • DIN / ISO: 72581 / 1
  • Current Strength [A]: 16
  • Fuse Type: Melting Fuse
  • BOSCH: Fuse
  • Item number: 1 904 520 018
  • Condition: New
Details
BOSCH Fuse 16A, 32V
Article number: 1 904 520 018
£ 0,21
Price per item
price incl. 20% VAT, excl. delivery costs
J SERIE BOSCH 1 987 529 057 Fuse 25A, 32V
Reviews - 3
Parts Details
  • Current Strength [A]: 25
  • Voltage to [V]: 32
  • Fuse Type: Block Fuse
  • Specification: J
  • BOSCH: Fuse
  • Item number: 1 987 529 057
  • Condition: New
Details
BOSCH Fuse 25A, 32V
Article number: 1 987 529 057
£ 4,85
Price per item
price incl. 20% VAT, excl. delivery costs

Popular posts

Subscribe to our newsletters

To get our latest news and tips, please, enter your e-mail: