The scheme for switching on the sound signal is shown in fig. 7-38.
Pic. 7-38. Sound signal switching circuit:
1 - sound signal;
2 - sound signal switch;
3 - relay for turning on sound signals;
4 - mounting block;
A - to power supplies.
If the signal strength decreases or wheezing appears, adjust the signal by turning the screw on its body in one direction or another until a loud and clear sound is obtained.
If the signal does not turn on, then check the F7 fuse, the reliability of the wire connection and the condition of the contacts of the horn switch.