Pinpoint Test C : No Sound From All Speakers: Notes
WARNING: This page is about a different car, the 2017 Lincoln Navigator and 2017 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.
Refer to Audio System/Navigation , for schematic and connector information.
Normal Operation and Fault Conditions
Refer to ACM in Information and Entertainment System .
When the ignition is in the START position, the ACM receives voltage on the START signal circuit and mutes the speaker output. This prevents voltage spikes from producing popping noises through the speakers. A short to voltage on this circuit causes the ACM output to be muted continuously.
Possible Sources
- Wiring, terminals, or connectors
- ACM