It's been quite a few years since I upgraded my stock Infinity head unit to a
Kenwood Excelon KDC-X599 in December 2016. The Kenwood worked out of the box and still works great today; it has a decent CD player, Bluetooth, etc.
However, my rear sub-woofers, which were not working
before the swap, still did not work after the swap. I recall plugging the cables into various outputs on the rear of the Kenwood to no avail. My sub-woofers are still not working today.
So, if I understand correctly what you're saying here
The first thing I noticed when I pilled the Factory radio was that the B section of the wiring plug is only wired for front speaker outputs (see pic) so it's a waste of time connecting the rear wires. After listening to my rear speakers I am guessing they are just sub-woofers, correct me if I am wrong but they produce sound with only front speakers output to the OEM amp
is that the factory amp drives the sub-woofers, meaning that one should not bother connecting the sub-woofer outputs of the replacement head unit regardless of what the replacement unit/harness instructions say.
This also means that I need to look at my amp as the source of my sub-woofers not working. Correct?