Hey guys I'm kinda new here to the third gen forums but I figured I should show y'all my ls build from start to finish (almost) I've already done a little bit of work I've also talked to QwkTrip about my wiring as this is my first fuel injected motor swap just to let ya know about the car and it's current state it is a 89 iroc z. I had gotten in a wreck and was lost didn't know what to do but didn't want to give up on my dream of building my own car so I searched for a front ends tube chassis kit and I found one so this will a be in preparation for that along with the 5.3 that will (eventually) be going into the car please feel free to give some constructive criticism and advise when needed!

 

Figured I should start with the wiring since that will one of the biggest headaches!

 

Nah, it's not just just another build thread. This is YOUR cool build thread!

Tell these guys what was in your last Camaro... I had to lift my jaw off the floor when you told me.

 

The wiring wont be too bad. Using a standalone setup?

 

I appreciate that man I used to have a 92 with a 454 bbc and twin 76 mm turbos mom had a 2md gen split bumper and grandpa had a 1st gen I was the 3rd generation to race hence why I got a 3rd gen lol then I sold it to go to UTI 😩 but now I want to build this one by myself and just to show grandpa that I actually listened when he was teaching me lmao

 

Yeah yeah I am going to use a holly Terminator Max or whatever it's called lol just don't want to cut the wrong wires 😂

 

Good luck! I'm almost finished with my swap now, too. There is something super satisfying about finally seeing that LS and, in my case, the T56 bolted in and the oil pan clearing the K member .

If you're using an 4th gen oil pan, I had really good luck with the UMI LS swap mounts with the stock k member.

 

Whatever you do just don’t start cutting wires. A stand-alone harness is pretty straight forward. Just need to find where to hook it to. Pocket has excellent posts explaining how to prep existing harnesses. I went with Speartech for my harness. There are a lot of vendors making standalones.

 

Well...i was at the garage tinkering around and I guess I'm just not understanding the wiring diagrams I have also just scared of cutting the wrong wires lol got any tips for me? I've been using the austins 3rd gen wiring diagram..any better diagrams out there?

 

If the wire goes through the firewall then odds are you keep it. If the wire just goes around the engine bay than odds are you remove it.

I cut the wires long and draped them over the fender. Then after the engine was installed I began moving wires back to the engine bay one by one until I was left with wires that I did not seem to need anymore.

If I made a bad choice then no big deal, just get out soldering iron and shrink tube and fix it.

 

First and foremost, read this thread before you cut anything

https://www.thirdgen.org/forums/ltx-...rt-finish.html

It is best to find the C100 pinouts. Not sure if its the same but here is one from an 88 Camaro


If this is different from your 89, then do some searching til you find it. Should be very similar to the 88
Basically, what Pocket says is you need to find all the wires you need to keep. Make sure you DO NOT cut any lighting or wiper wiring. Even if you do cut wiring, leave a few inches in case you make a mistake. The main wires you need to save are the RED wires A2, Purple wire B4, another RED wire G5 and Pink F4. These are the minimum. If you are using the dash gauges, you need the sensor wires. Others to keep are backup lights, Generator, Tach.
All wires going to the computer can be cut.

If you are using a standalone harness, you should wait until you get it before you start cutting. Most standalone only need maybe three wires to hook up: ground, Power, and Ignition You could also have your existing harness modified to fit your engine. Pocket used to do them. Not sure if he still does so you would need to check. Maybe someone else will chime in to recommend harness mods.

Someone sent me this but I forgot who but the info is good:
Power:
only your purple goes to the small post on your starter out of the C100 wires. Both reds go to the distribution block, they are inputs to your car from the battery. If those are not hooked to a distribution block, dash and everything else does not get power. Pink is a B+ OUTPUT as an ignition 12V source. So anything in a swap that says "ignition voltage" or "keyed hot" will be tied into that. In my swap I used the large pink wire as my main ignition hot for my main relay to power my O2S, coils, injectors, and MAF/trans if app.) for your battery from the back, you should have one thick wire going to a distribution block and have your C100 wires tie into that, and you can run another wire from the battery to your large post on the starter, or jumper off of the distribution block and have a short thick wire run from the dist. Block to your starter. You can use C221 pink wires as some ign. Hot wires. Remember if you use the thick pink wire, it is NOT fused so anything that is fed from my thick pink wire from the C100 I have fused at a home-made fuse block as a safety precaution.

 

I'd suggest saving the wiring for later. Never know when you'll shift gears when a good deal on a big part pops up

All of the wiring threads are in the LS swap sticky. I'd start on the 3rd gen prep thread and use the 3rd gen diagrams from the Add'l info thread. The start to finish threads cover breakdown and rebuilding of the LS side of the harness then mating to the 3rd gen half. There's an immense amount of info that you won't get in one skim, so read them a few times. If you get the basic concepts of why each step is done, then you can apply it to any engine swap

Also, I still build new PnP and 4th gen adapter harnesses if you just want to push the easy button

I'd suggest starting with the teardown and chassis repair. If the car will see mostly street miles you may want to look into replacing the crunched chassis with another strait piece instead of a tubular front clip. If not for the safety aspect, then liability. No telling how an insurance co may react to a custom partial frame in the aftermath of an accident

 

I'd suggest you do what Pocket says. You can disconnect the C100 easily enough. One half has all of the lighting connections (smaller half). This can be just draped out of the way. The larger half has all the engine controls on it. You can disconnect all the plugs and remove the whole harness to get it out of the way. It looks like your engine is out already so putting tags on each wire is too late. You can always go by the wire color at the C100. This is the harness part you would send out to Pocket if you decide to go in that direction.

Have you made a decision yet on what kind of engine harness you will use? Standalone or reworked?

 

First of all I'd like to say thank you guys for the overwhelming amount of information!! I greatly appreciate it and to answer your question I'm going with a Holley Terminator x max I got a great deal on one I couldn't pass up lol

 

The Holley setup is basically a standalone system so just keep track of the Pink wire and figure on setting up a power distribution block. To fix the front end, you will need to remove everything. I found that with all those front end body parts off, it was easy to run wires, set up radiator and fans. So if you don't want to do what Pocket recommended (fix front end first), at least remove all the damaged stuff and set up engine and wiring and ask any questions as they come up. I can answer some but not all. I swapped in a Gen V LT1 so my fuel system is different. Other then that, the swaps are very similar.

 

Sorry to keep you all waiting I've been stupid busy at work but im off till Thursday so I actually have time to go work on the car thank the Lord 🙌 lol so just be ready for more questions as I'm sure I'll have some

 

Just talked to my local chassis guy he said he's booked till the end of February but I'm on the list! So the front end is basically taken care of. Also that gives me time to go through the wiring and get all that sorted out also trying to figure out what these 3 blocks are going to so I can get to the c100

 

I think those are relays. The square one might be fuel pump. Throw that one away forever, it's a fire waiting to happen. The other two might be radiator fan, MAF sensor, or ummm.... gosh, I can't remember. (And it does vary by car)

What I did is check for wire continuity to figure out what is what. For example, unplug the connector at the fan and check for continuity of wires to the plugs at those relays. One wire will go to chassis ground, and the other will go back to a big relay somewhere in the engine bay. You'll figure out which one is fan relay in about 30 seconds.

 

.... or ask Drew. He knows all this stuff. The dude is a walking encyclopedia.