Circuit/System Description
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The amplifier receives PWM signals on the antenna 14V switch supply voltage circuit at varying duty cycle percentages for controlling the ON and OFF functions of the amplifier. The radio outputs a low duty cycle signal to produce an ON condition at the amplifier. The radio outputs a high duty cycle signal to produce a OFF condition at the amplifier.