I am doing my first ls swap on my 84 Camaro z28. I got a new efi system so the engine part is covered. The thing I am struggling with is how the wiring is going to work on the rest of the car from head lights tail lights and the inside electronics. Ik the c100 has something to do with it but don’t know what to do

 

Your headlight harness is not affected by the swap at all. Just the engine harness. Take a look at the stickies in the LS swap forum and start reading up.

 

There are two large red wires in the engine bay at C100. Follow those back to the beginning and you will find they have fusible links and ring terminals at the ends. Those wires power all your stock chassis electrical systems (lights, doors, windows, gage panel, etc).

The other wire you need to keep is another large red wire at the HVAC fan relay in engine bay. This is power for "high speed" of the HVAC fan. Follow that wire back to beginning and it will also have a fusible link and ring terminal (possibly shared with one of the other wires but not always).

A real GM shop manual (published by Helms) has excellent wiring schematics that will help you understand your car.

 

Also wondering what the pink wire does and if I need it

 

I did an LS swap on my '84 Trans Am. Here is a post that you might find useful.
https://www.thirdgen.org/forums/ltx-...ml#post6108217

Some of the conclusions that I made at the time may not be accurate. The C100 and C207 chart that I posted should help, though. And as QwkTrip told me during my build, the "F4 (Pink 12 gauge wire) is not fused at the fuse box, it is straight through the key switch and on one of the main fusible links. If it shorts then you lose the fusible link and half the fuse box with it." I ended up using that wire, and its first connection out of the C100 is a fuse.
I cleaned up my C100 plug and removed the unnecessary wires. What was left was gauge inputs (oil pressure, coolant temp, and tach), windshield wipers, starter solenoid, power distribution block, and power to the headlight switch (I think). The reverse lights were routed through the C207 plug which is on the passenger side, and that wire connects to the transmission. The speedometer is cable driven, and I bought a cable connection kit for my T56 transmission.

This post with diagrams from Pocket helped me understand the power distribution block:
https://www.thirdgen.org/forums/ltx-...ml#post5332509

 

theres two hot wires going to the starter do these feed the c100