Wiring Harness Race Mod
 

So i looked in the stickies, and couldnt find anything, and i searched and nothing again. is there a write-up on pulling the wiring harness apart to get rid of all the un used wiring? i deleted a lot of stuff from the car and dont need all the extra wiring, im just afraid to butcher the harness. thanks for the help guys.

I used painters tape and started labeling sensor connections. Then, just find a wiring schematic and start trimming.

I got a wiring schematic from AllData it was pretty good, they have the body harness schematics too.

Did you just trim the harness or did you remove the pins from the pcm too? If I just trims away the unused wires I think it should be pretty easy.

I removed the pins. Found plenty of diagrams/writeups/pin assignments on this site.

Also depends on how clean you want the harness. I yanked both internal and external harnesses, layed them out on the floor and chased each wire to the source.

Your finger tips are going to hurt ;-)

I removed pins also

Plan to spend alot of time on it, get a wiring diagram and take your time

I think I have about 40 hours mine

yea definitly not something you want to hack at. take your time.

you'll definitely want to pull the pins out. dont leave anything hanging there that can short out. i just cut all the wires out first then when i was done, removed all the pins of the cut wires. took only one night using a schematic. i think i removed a good 40 wires. i also made it a stand alone and put the computer inside the car.

i suggest spending the time working over time rather than the hours pulling 10lbs or less of wire and buy your self some nitrous or other go fast parts.

I remember reading on here about a company that did this for you. You just sent them your harness and they removed the wires you didn't need and sent the harness back with everything labeld where it goes. Can't find it though?

Also I think a lot of people here aren't really worried about the weight of the wires rather than cleaning up the mess of unused wires and connectors.

I typed out a response last night and deleted it on my phone on accident...

I went through and labeled all of the plugs when I removed them. I tried using alldata, but for me it didn't make any sense. It helped on a couple things, but mostly just confused me.

When I started I would choose a plug that I knew I would no longer be using. I then chased all of the wires from that plug to see what they tied into. The factory harness has a lot of odd circuitry. Weird things tie into each other like the power seat and the rear defroster. Follow all of the wires before you start trimming them.

I removed all of the wires from the connector that plugs the interior harness into the underhood harness. I left most of the ones running out of the fuse box though. If I ever need power I can just tie into those.

You are right, Speartech, there a sponsor on here -----> http://www.speartech.com/ Its $450 for them to rework your factory harness. And from what i hear hes a ex-employee from GM. He was a wiring engineer, we bought a 4l60e swap harness for my buddys ls1 car and it was nothing but QUALITY. He uses all GM factors plugs and seals. Little pricy but worth it IMO knowing that nothing is gonna short out or fry a pcm.

im thinking im giong to just remove the enitre harness internal and external and try to follow along with the schematics and trim what i dont need. i really want to engine bay to be clean looking, and get rid of what ever extra weight i can...

It wasn't so much about the weight for me. I just wanted a clean looking engine bay with no loose hanging wires and plugs.

Next project is to get rid of the OEM fuse boxes and replace and relocate them inside the car. I have to pull the engine anyway.

It does take a massive amount of time. I am partially color blind and it made it a lot more complicated and difficult.

yeah i can see where that would complicate things quite a bit when looking at a wiring diagram that has all the wire colors listed.

i am color blind...lol maybe i will just pay someone to do it for me lol


or maybe not. i just called speartech, and their harness is a stand alone setup. it wont plug into any of the external harness. so no ignition, guages, lights etc. so back to the drawing board. i guess i am going to be pulling it all out myself... if anyone in south florida wants to help ill buy the beer!

The engine harness is nothing when you dive into doing the Chassis harness.
Next time around I will do a Painless setup.

thats what i did was turned my stock engine harness into a homemade standalone harness keeping the gauges and just workin through the harness witha diagram and goin by what sensor plugs i needed to keep then shorten/lengthened the wires accordingly and then used a painless harness for the chassis ive got lights,radio and power windows and mirrors on the painless harness and then just the essentials on the engine harness with the painless setup i just have a fuse block on the inside firewall with my other relays and nitrous acc in the glove box...i ran the chassis harness up on the inner fender on the pass side down through the core support and then ran the engine harness out the divit where the center bolt for the hvac box was just used a small hole saw behind the intake theres barely anywires under my hood just running to the injectors and misc sensor,also with out the hvac in the way my coilis are under the dash