HA!! That ground wire actually DIDN'T tee into the factory wiring harness like it looked like. I cut off all the zip ties and separated everything so I could see what I was doing.... I started pulling on that ground wire until it ultimately came out from behind my amp rack, hooked to nothing. It had a open end connector on the end, indicating that it was piggybacked onto the ground of the amp I removed. I was finishing up this job last night and it was getting dark. I must not have noticed that other wire.

AAAAAGGGGGHHHHH!!!! I wish I would have figured that out before I laid awake for 3 hours last night, completely puzzled.