help with VSS speed wire for OEM nav install in a Prius III (three) w/ JBL non-nav

Folks, I need some help I got a good deal on an 2010 OEM navigation system and already installed it into my 2011 Prius III (three) the one with built in JBL amp, non-nav. The harnesses were simply plug and play except for the VSS/speed wire, reverse, mic, and backup camera, so I was pretty stoked. The reverse, mic and backup I've taken care of, but unfortunately the system is a bit buggy (I talk more about this below) because the VSS/speed wire is still not attached, I can't find it.

I've done many searches on PC and a couple of members have identified where they found their VSS/speed wire. For the Prius II owners, its already part of the factory radio harness (you guys are so lucky!). Unfortunately for the III that comes with the JBL amp, it's missing on the harness. Instead, from what I have read from a member GreenCurry, who owns a canadian prius with JBL amp non-nav, that it was the purple wire off the JBL amp harness under the passenger seat. I tried tapping into that purple wire but with no luck. Going into the diagnostics within the navigation system still shows a pulse of 0 So I did a google search and someone mentioned that the VSS wire is located near the left front speaker under the dashboard, but not sure which trim that was for.

Can anyone who has a Prius III with JBL amp non-nav please tell me where our VSS wire is actually located? Those that have this III + JBL trim and has successfully performed the Rosen, Kenwood, Sony, etc. aftermarket installs, where did you tap into the VSS/speed wire?

For now my OEM navigation system is working fine for music, but navigation not so much. When I input a destination it will not give me voice turn by turn prompts and will not reroute, as if it's waiting for me to be on course in order to do so. I'm thinking it has something to do with the speed wire not attached?

Anyone that has done the VSS bypass via switch, do you get the same symptom of no longer get turn by turn voice prompts when you bypass VSS?

Thanks for any help you can offer! BTW, I know many members here do not like the OEM nav, but I just love the bluetooth streaming and the clean OEM look!

UPDATE: after more troubleshooting (multimeter using AC to check for pulse) the problem ended up being the custom harness I installed. I verified with a mutimeter that the VSS speed wire IS in fact the violet/purple wire hooked to the JBL amp. My custom harness was just wired in the wrong pin slot. After the fix, voice turn by turn directions finally work! A cheap multimeter saves the day once again!