Need some wiring help

[Iceburgh]

This is my first LS swap and I am not 100% sure what is going on but I am getting closer.
First my background. I have built 7-8 trucks/street rods. Not much I cant or haven't done but as mentioned this is my 1st LS engine. The reason it is my first is due to lack of understanding of the electrical system hat runs everything.
I have a rebuilt LS1 with a rebuilt tranny along with a new computer that has been flashed for this motor knowing it was going in a street rod.
The person that sold it to me had it running with a video that he sent.


My questions are a few about some of the wiring. Most connections I can figure out by process of elimination. But not all . Can some of you guys help me understand where someof these go to or from.

1st the reader.... I know what it does but can you tell me where it wires to.
looks like 4 prongs are used


1 orange 2 black and 1 green wire


Next are 7 thin wires that come from the main harness that has all other plug in connectors.
they are Dark Green, Light Green, White, Grey, Brown, Light Blue, and Purple



Next is this obvioulsy plugs to something but not sure where or what




And Last the fuse box
1 Blue wire, 1 Pink or light red, 1 Heavy guage red ( I am assuming to battery positie) 1 red light guage ( I am assuming a switched hot ) 1 black, 1 yellow and 1 plug. Not sure on any of these.


Thanks in advance for any help.

[Custom 68]

There are several of us on here that have done the swap. Some with aftermarket harness and some that modified the donor harness. With the later there are several resources that will allow you to trace back to the computer and know what each wire does.
I will stop at that, I could guess (and probably be correct) on several of these but it looks like a modified harness I would assume the person that did it for you should have included some form of instructions. I have modified some and marked everything as I went. I took one to my buddy and it all went together.
It looks like somebody did a really really nice job but forgot to mark them. Where did you get it and have you got ahold of them?

[BR3W CITY]

Ya I'm surprised; that harness looks pretty cleanly made...just to not come with instructions lol.

Unfortunately, there is no guarantee that the colors used with directly correspond to any stock colors...but a good place to start is by grabbing a install manual off the web from someone like Painless (who makes thousands of harnesses). It might not be 100% the same, but identifying the main branches should help you narrow down what to look at. Take it one step at a time, like take the branch for the trans and do it all, then move to the next branch.

The big round plug looks like an auto trans connector, is there another flat or square connector on that branch of wiring?

[custom70]

That big white round plug is the transmission plug. As far as the other wires they are custom it appears. Go to www.lt1swap.com and see if you can find the pin outs for your harness (camaro etc.) You can then trace each wire to where it connects to the PCM plugs.

[dayj1]

Lots of good advice so far.

On the DLC connector, the orange wire at pin 16 is 12V hot at all times. Pins 4 and 5 (black) are ground. Pin 2 (green) is the serial data from the PCM.

For the rest, you'll either need "instructions" from the harness builder or some time and a voltage meter to "buzz out" the wires. Some of the colors match factory colors for a DBC harness, but some don't. For example, the white wire is usually the tach signal, purple is for torque converter lockup at the brake switch, dark green is serial data to the DLC. Other wires that would normally go into the cabin of the vehicle with the aforementioned wires would be things like VSS, oil pressure, MIL control, etc.

[Iceburgh]

thanks guys it is a start.
I am happy with what I got just need to reach out for some directions I guess.
Everything is new except the MAF. 465hp shipped to my door for $4800.
Might be steep not sure but it has zero mile and has been started and tested with video.....piece of mind compared to what I have seen in scrap yards for almost as much.
Guy is from the Denver area.