Its a rectangle plus on my 99 harness. It houses the orange pcm power wire and the white tach wire(along with a few others) well after converting my harness last night I needed to remove those wires to splice them into the RX7 body harness. After removing all of them I was left with a gray/black wire which I traced back to Pin# 53 on the RED connector and its the SPARK RETARD SIGNAL. Does anyone know where this goes..or used to go on the LS1 Fbody?

 

most likely it is going to the traction control module.

Ryan

 

hmmmm

 

 

That wire used to go to the Electronic Brake Control Module. You can get rid of it. If there are any others you're not sure about, just let me know.