The causes of malfunctions of sound signals can be the following: the switch does not work or sticks, the sound signal or the relay for turning on the signals is damaged.
To detect a malfunction, check the reliability of the wire connection, the condition of the switch and relay contacts. Clean contacts if necessary. Replace defective sound signal, switch or relay with new ones.
If the signal strength decreases or wheezing appears, check if the battery voltage is low. If it is normal, then 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 adjustment does not eliminate wheezing or the signal is intermittent, then disassemble the signal and clean the contacts of its interrupter.
When assembling the signal, it is necessary to install the previous gasket between the membrane and the signal housing so as not to disturb the gap between the core and the armature.