Freightliner Cabover Wiring & Fuse/Relay issues

I have a 1996 Freightliner Cabover with several issues I’m trying to troubleshoot.

VIN: 1FUPBSYBOTL672131
3406 5EK Cat

1. Can’t believe how little information is available on these trucks online. When running the VIN, it says model is High COE but doesn’t give actual model. I believe, reading through history, it’s a 1996 FLB, which there is even less info for. Any info or leads to better info appreciated.

2. I am replacing headlights and can’t figure out wiring issue. With adapters and testing, I figured out right side. It has outside light at dim and both on at high side.
Driver dim was working, but after wiring inside light every which way, neither work on driver side when key cut on. Dim driver does work when key off, along with both passenger lights.

3. The relays and circuits panel under doghouse is a cluster to say the least. Apparently a shop got ahold of it a few years back and did a number on it. The plastic piece that tells what each does, I believe to be laid in upside down, but am not sure about anything. Can’t find any diagrams. Any help or direction would be appreciated.
I have put a voltage tester on all the hookups and am getting appropriate levels to all lines, but not sure if that’s how to test the (not fuses but circuits?)

Several others issues I might address if anyone in here can help with these issues to start! Thank you for taking a look

 

Update: this afternoon I was trying to show someone the issue, and none of the lights work except the orange blinker lights in each bezel do come on.

This makes me think I have them wired incorrectly, but I also think there’s a short somewhere along the line (which will be a doozy to find).

 

That’s all incredibly helpful information, and a good reminder to do what I knew I should’ve done to begin with!
This was going to be an update to better, and like a dummy, just assumed plug and play haha.
Thank You!