Horn: Description and Operation

Horn

Two horns of the trumpet type are located behind the grille under the radiator cross-member. The horn switch is located in the centre of the steering wheel.

The horns are tuned to different frequencies. The horn marked H is high frequency and the one marked L is low frequency.










The horn switch (336b) is connected to SID pins 3 and 18. When the horn switch is pressed, the SID grounds pin 17 and the relay (68) operates. Power +30 is fed from fuse 10 through the relay (68) to both horns (40).

The horn is also used for confirmation of "TSL"-locking (Theft Security Lock) of the car. The SID unit receives information via the bus from TWICE and the horn is activated.

Diagnosis
For diagnostic help, see Saab Information Display (SID) as found under Driver/Vehicle Information Display testing for the symptom: Horn Failure/Steering Wheel Switch Unit Failure [1][2]Symptom Related Diagnostic Procedures