I know some experts who answered some questions on the topic of relocation HU are here so allow me to paste my question here:
"I think I did everything described above (didn't end up using metra 70-9003). So at the end, Metra 71-9003 has only two wires, one is the 12v positive and the other one is the ground. I actually spliced from the technic harness that's dealing with the JBL MS-8 for 12v power. So I did not get the 12v from the battery because I don't really connect this OEM HU all the time, but just to know that I have the capability to do so, if ever needed. The OEM HU will end up in my basement.
After powering up, the radio powers up, one red light comes up from one of the holes for MOST cables.
So I plug in both fiber optic cables. There is no response by pressing "Menu" on the OEM radio. Does that mean something went wrong? Obviously I did not connect CAN High and CAN Low but if the the MOST cable loop is complete, does that mean it satifies the need for "software updates"?
Or do I have to connect CAN High and CAN low? If so, how do I do that?
Then,, how do I know that the MOST cables actually are working? Is there a way to test it?
Thanks for any inputs."
The original relocating HU thread is: