See
Figure 1. The maximum sidecar volume is dependent upon the volume of the passenger speakers (a level established using the handlebar mounted +/AUDIO/- switch with the FADER function) or the passenger headset volume, depending on the position of the fairing SPKR switch. Rotating the volume and press to transmit (VOL / PTT) knob on the dash may lower the volume of the sidecar speakers but will not raise the volume above the master volume level.