Good Information About Car Horn
Repairing a faulty horn;
stopping a continuously blowing horn
if your car horn fails, repair it as soon as possible – it is illegal to drive a vehicle without an audible warning device. The most likely fault is a blown fuse.
A blown fuse The fuses are mounted in a box or on a panel usually on the bulkhead under the bonnet, or under the dashboard.
If the fuses are numbered, consult the car handbook to find which one protects the horn circuit. Alternatively, you may be able to see which one has blown.
Replace the fuse with a spare marked with the same amp rating – there is usually a spare in the fuse box. If the new fuse blows, there is a short circuit in the wiring which must be rectified by an auto – electrician.
If the horn works, check with your handbook to see if other circuits are protected by the fuse. Operate each in turn – one may be causing the fuse to blow.
If the fuse has not blown It is possible that the wiring connections to the horn are corroded and must be cleaned up.
Pull the wires off their connectors, remove the horn and clean the terminals and connectors with fine emery cloth. If there is rust on the horn bracket at its mounting point, clean it and the mating area of the car body with a file and emery cloth until the metal of both is bright.
When a horn stays on If a horn will not stop blowing, tap the horn button – the switch may be stuck. If that fails, open the bonnet and disconnect the wiring to the horn. If the horn is difficult to get at, disconnect the battery to stop the horn blowing while you immobilize it.
While the horn is removed, test it by connecting its terminals to the battery terminals using two lengths of insulated wire. If it works, bolt it back in position, connect it up and try sounding it again.
Finally, if the horn still fails to work, suspect the push – button switch. Often this forms part of a multifunction stalk switch on the steering column, and the complete switch on the steering column, and the complete switch unit must be replaced. Where the horn is operated by a button at the centre of the steering wheel, remove the button; clean and adjust the spring contacts beneath.