At the point where I can start wiring

[Slowguy]

I’m a little nervous that I’m going to have issues since my truck is so far from original. Any suggestions or recommendations before I begin would be greatly appreciated

I purchased the American autowire kit for this truck. I don’t have the original engine, I have a turbo ls. It has its own complete engine management system. As far as I can think I’ll only need a few things from that end like speed, oil pressure, coolant temp, battery level, brake switch. Hopefully I can figure that out.

I also have a nu vintage gauge cluster that’s all put together and ready to install. I also have the 4l80e trans but I don’t know if that will need tied into the wiring in any way.

Any tips would be great. I ordered a crimper I read about in another thread.

[Accelo]

My advice is to be very careful about keeping the various packaging together. Finish one section as best you can and then move on. Individually package them and then keep them all in a box with the wiring directions on top. You will need them often. The LSX wiring didn't require much interfacing with the AAW. The 4L80 will interface with the computer. Only output required from the transmission is the speed sensor. The AAW comes with the wiring for aftermarket gauges and a twisted pair wiring for the speed sensor. I used a power probe to test every circuit I could. It has the ability to provide power and a ground at the tip. Of course, a length of wire to the battery would work. If you make one fuse it at the battery. FYI, the Power Probe has a circuit breaker in the handle. Don't be afraid of calling the Tech Support Line at AAW. They are helpful and easy enough to contact. I recommend starting at the rear tail lights. You will get some experience with the crimping process that way. AAW is fairly generous with extra wiring ends so you can make some mistakes.
I really liked the Mega Fuse that is included in the kit. Gave me options for power accessories without tapping the battery cable. If you, do it at the battery it looks like a back yard add on and if you use the starter end for the wiring is long and difficult to get to and exhaust tends to cook the wiring. I recommend some shrink tubing and the plastic sleeves to clean things up. Actually, wiring is straightforward enough. Making it look good is the difficult part. Planning ahead where your computer(s) will mount is paramount to getting a clean system install.
One more thing I thought of. There are at least three types of spade connectors. Two are different widths, very close to each other and easy to mix up. Headlights take the wider of the two. There are a;sp two different crimps ends on the connectors. One is wider for crimping two wires into the same terminal. They have pictures but didn't really explain the different usage very well.
Cheers

[HO455]

The only thing I can add to Accelo's post would be to create a wiring diagram of how you plan to wire the truck. Copies of it will be helpful as a check off sheet as you complete sections. This is especially important if the project goes on for an extended period of time. Plus they will be invaluable for troubleshooting problems that will invariably pop up years from now.
And if you ever decide to sell the truck a custom wiring diagram can be a good bargaining chip to get your asking price.

[LS short box]

On a couple of LS swaps I've used Painless universal chassis harnesses. I know its not a AAW but similar.
Since you are going LS your LS engine/trans harness is basically stand alone. The LS ECM will need a constant 12 volt and switched 12 volt in start and run. The LS harness should supply a tach and speedo signal. Also a TCC wire. The LS ECM should supply a trans harness. Big multi pronged plug for the valve body and plug for the VSS signal.
Oil, volt, fuel and water temp gauges are kind of stand alone. Oil and temp just run off the supplied Nu Vintage senders. The volt gauge just needs a switched 12 volt. Fuel gauge check with Nu Vintage. I'm guessing but it will need a 90 ohm sender in the tank and 12 volt switched..
If you still have the old stock interior wiring harness clip off the connectors for things like the heater, wipers, head light switch and such so you can marry them into the AAW harness.
Make sure you go over board on good clean grounds. Battery to engine. Engine to frame. Frame to body.
Great advice above on making a basic drawing of your wiring set up for future reference.
Good luck with your project.

[Peanut74]

The only thing I can add is to lay it out on the floor. From there you can determine how you route your wires. Keep your old harness but don't cut off any connectors unless you need them. This way you won't lose them and also label them to make sure you can match the connector to the part. Most of all take your time.
.

[71CHEVYSHORTBED402]

The way I did it is ID every connector. Get yourself some 56 series terminal tools if you don't have them, and if you're like me, spend $180 for the correct crimpers just to install 1-2 terminals

[Accelo]

Thanks for the tip 71chevyshortbed402.
I found this vendor after you named the type of connectors (56 series).
https://www.customconnectorkits.com/...selling&page=1
They have it all including the retainers for the black plastic looms the factory used.
Great source if you need any terminal replacements.

[CG]

Originally Posted by Slowguy

I’m a little nervous that I’m going to have issues since my truck is so far from original. Any suggestions or recommendations before I begin would be greatly appreciated

I purchased the American autowire kit for this truck. I don’t have the original engine, I have a turbo ls. It has its own complete engine management system. As far as I can think I’ll only need a few things from that end like speed, oil pressure, coolant temp, battery level, brake switch. Hopefully I can figure that out.

I also have a nu vintage gauge cluster that’s all put together and ready to install. I also have the 4l80e trans but I don’t know if that will need tied into the wiring in any way.

Any tips would be great. I ordered a crimper I read about in another thread.

My brain just exploded ... thank goodness I dont have something like this weighing on my pea brain .... Good Luck!

[Accelo]

Slowguy
I think you made the correct decision going with the AAW harness.
They are a lot of work to install. With the addition of the vintage gauge cluster, which I assume is a digital dash, it will add the circuits you need to get it functional.
However, if one is just adding a LS motor to a mostly stock truck I would recommend a stock replacement harness. Way faster and easier to install.

[cj847]

From your post I can't tell what you know about wiring. Or where you are at on the build (ie is it running with the old harness now or a completely stripped down truck waiting on everything) I will post some general information I think might be helpful.

For the most part, the autowire or any aftermarket harness install is the same regardless of engine. Just be patient and follow the instructions and test every circuit.

I think it is important to know the LS wire harness (you can find tons of info about that here including the wires that need to interface with the autowire here):
https://www.lt1swap.com/

I have seen swaps wired with 2 relays a few fuses and 4 or 5 wires from the LS harness. Or a separate relay/fuse box with a half dozen relays.

Depending on steering column and general preference you can wire your neutral safety and BU lights per the autowire instructions or off of the 4L80, but I don't dare try to explain it on here.

Once you've finished you won't be scared of wiring any more, but you may not want to do another.

EDIT: After I posted this I got to thinking about the LS swap in my Willys. I had a plan for the complete wiring harness going in and still found some stuff I needed to change. So, I am going to recommend that you have an understanding of where you are going with the build and hence the wiring. The things that I feel you need to understand:

-Do you understand the charging system of the LS? Depending on year there were different systems to limit overcharging. Our trucks ran with like 30-50amp alternators/generators. LS will have a min of 100 amp. They will overcharge and destroy your battery if you can't limit the charge.
-What gauge package are you using and where are you getting the signal?
-Where are you getting your BU and NSS signals?
-What kind of harness is on the LS (cut down factory or aftermarket)?
-How clean is the install to be (show truck vs a nice driver)?
-Are you going to run the A/C using the PCM or a separate aftermarket system?
-Are your wipers factory of aftermarket (the trucks ran power to the motor and used a ground to run, some aftermarket run power to the switch.
-etc
-etc

[LS short box]

I typically buy either Speartech or Howell wiring LS harnesses and they supply the ECM and TCM. They have four fuses in one fuse block. Two relays. One four the fuel pump and one for the cooling fan. You can spec out another relay for a second fan.
As far as wire coverings go I like the split braided type. Get it in different sizes for different
sizes of wire bundles.
Yeah wiring is not my strong point but as said above take your time.

[BigBird05]

One special point is the computer needs a clean ground. I. E. the ground should go to the battery. Do not splice it into any other ground. Most grounds are noisy (dirty). Computers don't like that because of the small voltage they run on.

[LS short box]

Don't want to start a debate here but I've never had to ground the ECM itself. I believe the ECM gets it grounds thru the wiring harness that are bolted to the back of the cylinder heads.

[BigBird05]

I was talking only about the wiring harness. I would not use the back of the engine block for a computer ground. I would go directly to the battery.