I just recently wired up my new Alpine 9883 with DCI and PnP wiring. All the dash controls work except for MUTE. The MUTE light will toggle on and off as I press it, but there is no change in volume. It's the same whether switch 3 is ON or OFF. Checked the wiring and mute function on the alpine and everything seems to be fine.

I'd appreciate any help or suggestions. Thanks in advance.

 

My mute doesn't work either. I just assumed that mute wasn't a feature the DCI preserved.

Since I rarely mute and never mute while driving I just reach for mute on my HU.

 

Problem solved!

The blue wire pin (mute button) on the PnP harness that connects to the dashboard socket was bent. I bent it back in place and now everything works. Audio interrupt is a great feature and so is SCV.