So my old HU died on me. 2010 G37S with Bose/ Nav. Got the black screen of death randomly. A/C and back up camera were the only things to work. Found a MATCHING replacement HU on ebay and changed everything out. Now my screen and everything else works but I am getting no audio. Not even able to control the audio (volume up and down not working) on either the dash or the steering wheel controls. I am not able to adjust any EQ setting at all. I am able to switch between BT, Radio, IPOD, and XM Radio but not able to hear anything. There was a few open ports on the back of the HU but all the plugs from the harness were already connected. I tried disconnecting the batter for a bit and still nothing. What else am I missing? Is there some sort or reset I need to perform? Do I need to do something with the AMP?

 

I would double check all connectors to make sure they are in the right location and fully plugged in. The one connector (M201, the 20-pin) can be a little tricky to get locked into the headunit and that one, typically, is for the audio/sound signals to the Bose amp as well as the steering wheel control circuits (A&B).

ALSO, did you retain your stock AC Amp (the rectangular box that mounts onto the headunit) or did you swap that out as well? The AC Amp has two connectors that are IDENTICAL and can be very easy to mixup. You might want to check those two connectors and, if you removed your stock amp, reinstall it.

 

Sounds like harness is bad or loose