I’m working on a 1992 Camaro (3rd gen) with an LS swap using a PSI conversion harness, and I’m trying to power up the factory body harness / fuse block for the first time.



The battery has been relocated to the rear of the car, and I have a front power distribution block with constant 12V available.



Right now I’m trying to figure out where to apply the main always-hot 12V feed to wake up the factory fuse panel.



Looking at the fuse block, I see the area labeled BAT next to the RADIO fuse and the PWR ACC section, but I’m not sure if that slot is the correct place to feed the main battery power for the entire body harness.



Questions:

1. Where does the factory main battery feed enter the interior fuse block on a 1992 Camaro?
2. Is it supposed to be fed from the back of the fuse panel through a stud or large terminal, or through the BAT slot on the front of the fuse block?
3. What wire in the factory harness is normally the constant battery feed (color and gauge)?
4. What wires should I look for that correspond to:
   • IGN / Key ON
   • START / crank
     
     
5. If I want to power the body harness and starts testing test lights/wipers/etc, where should I safely apply 12V? I was going to use 12v with a 100a breaker to power the body harness but I don’t know where this needs to go

The car currently has:

• rear battery relocation
• front power distribution block
• PSI LS swap harness
• factory body harness still intact

I just want to wake up the stock body harness and fuse panel safely before wiring the ignition switch.



Any guidance from someone familiar with 3rd gens would be greatly appreciated.

 

S

see body harness that goes through the firewall

 

After more reading it looks like the body harness power is going through the c100 engine harness first. Could I simply buy this connector and plug it in with a pin out to the main power distribution ? And my body harness would be powered ? Or is there an easier solution ?

are there any grounds I also need to replace if my c100 engine harness connector is missing ?

https://www.ebay.com/itm/204388511304

 

use the search bar at the top, all the wiring info you seek is in here.
it may take a bit of research to find what you need, but its all fully documented within this forum

 

On my '89 Firebird, all the chassis is powered by two 12 AWG red wires that go through the C100 connector. Fusible Link 'A' runs most the lighting and such, and Fusible Link 'B' runs the dash, HVAC fans, and other things. Both these are connected to power distribution in the engine bay. I cut off the fusible links and tied the wires directly into my new power distribution. Sorry, I don't remember the pinouts in the C100 for these two wires.

 

Source another used 90-92 engine harness. Engine type doesn't matter

Then read this

https://www.thirdgen.org/forums/ltx-...p-3rd-gen.html

 

https://www.thirdgen.org/forums/ltx-...1-harness.html

 

Yes, the power is coming in through the C100 connector. Yes. You could buy that eBay connector kit but to me, it is very pricey for what it is. It does have the items that you'd need and you don't have to do any research to find the individual components but it is a lot of money for what it is.

August 2025, I purchased 5 of the engine side, C100 connector halves for less than $4.43 each from Mouser. Unfortunately, it appears that they are no longer available from Mouser and that makes the very overpriced eBay kit a little more appealing:

Aptiv 15492519


The metal terminals are inexpensive as well with the largest being the Metri-Pack 630 terminals currently selling on Mouser's website for 56 cents each:

Metri-Pack 630 terminal 12064735-L

I'm LS427/570 swapping my 1987 IROC and I'm going to be powering the interior through the C100 connector just like you're going to want to do it.

 

427 / 570 ?
what does that mean?

 

Chevrolet Performance LS427 7.0L 570 HP Long Block Crate Engines 19421004


I was lucky enough to get my hands on one of the last available LS427/570hp Chevrolet crate engines.



Here it is in the engine bay soon after my wife and I got it in.

 

Thanks for all the information guys. That was extremely helpful. I was able to find the connector that plugs in and I did trim down some of the harness. I will get to testing and first start in the new few weeks! I appreciate all the help

 

I've got a question, so I hooked up a racetronix fuel pump hot wire kit, do I need to re wire the stock fuel relay back in the car ? Or can I just run a key on 12 to activate the fuel pump?

 

Your new relay should be triggered off the signal from the engine harness. Most "hot wire" kits or LS swap harnesses come with a new relay.

 

The 5.3/4l60e are on a stand alone harness but the fuel pump is the racetronix hot wire kit. The fuel pump relay with the kit is now mounted by the fuel tank and plugs into the factory bulkhead behind the seat. How do i wire in the fuel pump relay to be activated by the key on?