Circuit/System Description

WARNING: This page is about a different car, the 2008 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.

Each of the audio output channel circuits (+) and (-), at the radio and at the amplifier if equipped, have a DC bias voltage that is one half of the battery voltage. Therefore each of the audio output channel circuits will measure approximately 6.5V DC when using a DMM. The audio music or talking being played on the audio system is produced by a varying AC voltage that is centered around the DC bias voltage on the same circuit. The AC voltage measured on these circuits on the output of a radio that is not amplified will be approximately 1-3V AC when using a DMM. The AC voltage is what causes the speaker cone to move and produce the sound. This voltage will vary depending on what type of audio is being listened to, talk or music, and type of music, and the volume setting of the system. Low volume and talk settings will measure around 1V AC and less, where constant music may measure 3V AC and slightly higher. In an amplified audio system, these similar AC voltage measurements may be slightly higher on the output of the amplifier, and the typical AC voltage readings at the output of the radio are less than 1V AC.