Our mobile autoelectrical service engineer may be booked to attend your vehicle on site to fault diagnose and repair vehicle horn inoperative wiring faults
Tel 07703 558610
TM27 : Vehicle Horn
Vehicles used from 1st August 1973 must have a horn that produces a continuous or uniform sound. If the horn does not work it is a reason for MoT test failure.
TM34 : Pressure / Vacuum Warning.
Vehicles used from 1
April 1983 can be fitted with either a visual or audible warning device to
indicate low air brake pressure.
There are various ways to wire up a vehicle horn. Either positive or negative supply may be switched.
A common method to wire the horn on negative ground vehicles is to provide a continuous positive supply to the horn,
the negative return circuit is wired via the steering column horn button switch.
When the horn button is pressed, the negative return circuit is completed, connected to chassis ground via the steering column causing the horn to sound.