Need Community help on AUX setting in COMAND

I purchased a Moker Bluetooth module for my 2011 C300 (w/NAV) and it wasn't receiving power when I plugged it into the AUX/30-pin port in the glove box. I RMA'd the first one, and it was the same story with the replacement. Now I'm thinking it's something wrong with the car rather than the Moker.
I went into Engineering Mode in COMAND and under the HU setting where it displays the status of the various media component, "Audio AUX" was greyed out, and "Video AUX" says off. I'm now assuming the reason the Moker wasn't powering on is because the AUX port isn't actually switched on.
Is there a fuse I should be looking for? Any thoughts?
Thanks in advance for any insight.
Rick


