LS swap Coil Ground question

[NorthState]

Afternoon Gents! I hesitated posting this question so I could comb the interwebs for an answer. Stumped, here I am! I’m working through the LS swap on my 1997 ECSB. I traded my 355ci SCB for a rebuilt 5.3 with a reworked factory harness. It looks cleanly done, and even has a contact name and number sticker on it, but I can’t seem to get up with the guy.
Since I did the Lextech 0411 pcm swap, Im putting the 5.7 harness on a diet regimen and in comparing the two harnesses, I came across an irregularity. On the RED connector, pin 55, it is supposed to be the dk green AC low pressure switch sensor wire. (Picture1)
This is confirmed by Brendan(lt1swap.com) and @Lextech. The problem is, on my “reworked” LS harness, this pin is a black wire that ohms out at each coil harness plug! (Pictures2&3) I found an ignition coil harness plug diagram, that I think may be the correct one, and it calls this circuit 550. (Picture4) However I cannot find anything with that circuit number. Many guys don’t bring the AC over to the LS swap, but I gotta think some have. Of course, I intend on double checking each wire location bc peace of mind is priceless.

Until I get the chance to sift through the whole harness, my question is two fold. First, is this black wire pin just misplaced? Should it simply go somewhere else other than R55? Second, since there are already places on the factory harness where common wires are spliced together (grounds, ignition hot, and 5v references), if it doesn’t have a stated home, can I splice into one of the grounds that include other grounds on one circuit?

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[0xDEADBEEF]

Each coil connector actually has 2 grounds, 1 for the spark itself that grounds to the head and 1 which goes to the PCM. If I remember correctly, which I may not. So, if you have one that traces back the PCM, that sounds correct to me.

 

[NorthState]

Each coil connector actually has 2 grounds, 1 for the spark itself that grounds to the head and 1 which goes to the PCM. If I remember correctly, which I may not. So, if you have one that traces back the PCM, that sounds correct to me.

Ok that’s good to know. I’m still learning as I go, so I need to find the correct pin to place it in the PCM. All I know at this point is that it definitely doesn’t go in Red#55.

 

[NorthState]

I’m gonna go to a local pull-a-part btw Christmas and New Years with my multimeter to run some ohm tests on stock LS harnesses in the yard. I suppose it’s the only way to accurately determine where this ground goes.