Truck air horns and electric horns for HGVs
Horn systems on HGVs fall into two categories: electric horns that draw direct current from the vehicle's electrical system, and air horns that use compressed air from the vehicle's air system or a dedicated compressor. Electric horns are the standard OE fitment on most modern trucks and are the simpler replacement option. Air horn kits are an upgrade or period-correct fitment on older vehicles, producing the characteristic deep tone associated with heavy trucks.
For electric horn replacements, confirm the voltage (24V on most HGVs), the mounting configuration and the terminal arrangement before ordering. Air horn kits require either a connection to the vehicle's existing air system or a separate compressor if the vehicle does not have air. Compressor-driven kits are self-contained and can be fitted to vehicles without an air system. Dual-tone horn sets are popular for vehicles where a louder or more distinctive sound is required.
Call our team to confirm the correct horn specification for your vehicle. UK nationwide delivery or same-day collection from our branches.
Frequently asked questions
What voltage are truck electric horns?
Most HGV electric horns operate on 24V DC, matching the standard electrical system voltage of heavy commercial vehicles. Some light commercial vehicles and vans use 12V. Always confirm the voltage specification before ordering a replacement horn, as fitting a 12V horn to a 24V system will cause premature failure.
Do air horn kits need a connection to the truck's air system?
Not necessarily. Compressor-driven air horn kits include their own 12V or 24V compressor and operate independently of the vehicle's air brake system. This makes them suitable for fitting to vehicles without an air system. If the vehicle already has an air system, the horn can be tee-d into an appropriate supply point, but this must be done carefully to avoid reducing available pressure for braking systems.
Is it legal to fit loud air horns to an HGV?
UK regulations require that vehicle horns emit a continuous, uniform sound that is audible at a reasonable distance. Air horns meeting this requirement are legal for road use. Multi-tone or musical horns are not permitted for use on public roads under Road Vehicles (Construction and Use) Regulations.
