Aladdin wire goes where?

[joefromperry]

I'm trying to figure out some stuff with the Aladdin system (#100) on my 2003 Signature. The two boxes in the pictures have various connecting cables, but as you can see, I have one purple RCA phono plug that has been disconnected. I would appreciate if anyone familiar with the system could tell me where to plug it in? The smaller box doesn't have any empty spaces, so do both ends plug into the same box? Thanks.

Edit: I'm not 100% sure the other cables are connected where they. should be, either. System doesn't work. I'm going to troubleshoot, but need the cable(s) connected first.

Edited March 29 by joefromperry
added info