Well here it is, i finally decided to do it, i hacked a wiring harness to remove all the unnecessary stuff when you go single turbo and remove all the emission stuff. That was one heck of a job, took a whole day but i am happy. I decided to do it the right way, not only cut the wires that were unused but remove them completly, including the pins that go in the connectors to the ecu. I had to strip the harness completly and tape everything back. You got to be carefull with such a job because some wires are spliced and splited at different places in the harness, like grounds and powers. You got to make sure you don't cut a wire or remove a spliter that will still be used.

So what i have removed is the complete rat's nest (twins and emission), the ACV connectors, wastegate and precontrol solenoid, AWS, fuel thermosensor, air pump and egr connector

I am going to order some stuff to prevent the heat from harming the electrical tape and the wires, some DEI stuff i guess, i'll order that tomorrow.

Here are a couple of pictures to show the before and after. You can also see the difference in the ecu connectors as far as how many wires are left. I also took a pic of all the wires and connectors i removed from the harness. Sorry for those bad quality pics, i am a better mechanic than photographer...

BEFORE


AFTER


In the harness there is some sort of silicon to hold all the wires together, that was the biggest PITA, those were stuck really good, no clue why they did that. Looks like they put silicon in just before they taped eveything together.




Here is all the stuff removed


finally, pics of the ecu connectors before (can't see really well)


and after


I'll take some pics when the harness is installed in the car.

 

Nice.

 

would there be people interested in getting the same thing done for their harness? I could get some brand new harness and modify them for around 1000, would there be some interest?

A new harness when doing a single turbo projet is always a good idea, after 15 years of getting heated up in the engine bay, they become very fragile and brittle, not counting the electrical resistance that went up at the same time.

let me know

 

hey guys. i know this thread is a few months old, but i was wondering if anyone knows of (or could create for me) a list of all the emissions solenoids and their colors/pins back at the ECU plug. it is taking me forever to trace down every wire from the wiring diagram to the harness. I am hoping someone else has taken the time to do this and document it for the rest of us to use.

my plan is to just pull every emissions/sequential solenoid wire out of the harness and hook up the 330ohm 1/2watt resistors to each wire back at the ECU to clean up the harness.

 

 

I'd be interested, seems like a fair price of a *new* modified harness

 

Already have a new harness but will eventually like it slimmed down.

 

id pay 5 bucks for a full picture tutorial of how to diy. but with the posts above and how much I have already started on maybe just posting for people on here.

 

You mean like this one.....I advertised the mod for $300 shipped long time ago. It was your working harness to me, and looks like this one back. Loom is very nice. Something like 24 connectors and 16 wires total.


Also the purpose of the Sealant is to seal off the wiring harness from the engine bay to the Cockpit

ALWAYS include several spare signal wires for gauges and spare grounds.



Later

 

For $1,000 that some person can build a harness 60x better.
The harness shown hasn't been modified for EMI, heat, gas/oil, etc. The GND's could be better too.

Anyone looking to do this can spend half the money and end up with a harness worth twice as much as a stock harness by using 55A cable and DR25.

Apex Speed Tech (apexspeedtech.com) would be an ideal place to build that harness per your spec and 60x better.

 

If you cut off the solenoid connectors the idle air control will not function. It shares a power with the gray solenoid connector. What I do for single turbo/non sequential cars is open the harness and rewire it.

 

He's right, I've done that a few times (open the harness and rewire & de-pin).

Gotta be careful.

 

Meh, do you really need the idle air control? All of the ls1 engines I put in sandrails don't come with them (well until emissions controls were mandatory).

 

After doing some thinking I might offer this as a service. Not crap either, full shrink wrap covered with a braided sleeve. My only issue is I'd have to remove the connectors and that is possibly something I could only feel comfortable doing with a new harness. So I would sell a new modified harness. Not sure if there is much interest. I'm not new to wiring, I wired this $185,000 dollar sand rail front to back.

 

I didn't see any 55A cable in those photos... What did you write it up with?

 

of course you didn't, its standard primary wiring for the chassis. The engine is in the back of the car. There is no need for it. The engine itself uses thermal cross-linked wire TXL. The wrap for the chassis where the wires aren't seen is standard heat shrink and the wrap for the engine is a braided wrap. Anything more for these is not needed at all.

As far as the rotary stuff I would use the stock wires, possibly throw a heat shrink for the first layer and finish up with a fiberglass sleeve, I haven't really explored my options yet. It could end up being a high temp shrink with a nice braided top layer for a nice look.

 

You should start a thread in the group buy interest section. The stock harness sucks, I'd be interested.

 

no interest in recreating a stock harness. think about that for a min.. you could copy the structure / branching, etc then reproduce that with wire worth paying for 55A.

Trust me, 55a is very useful jacketed or non jacketed... braided or not. given the jacket type, etc you can surely run much smaller cable (F1 & Indy Car are using 22awg - 26awg) for typical small draw / low voltage and signal producing a much lighter weight harness and easier to work with. even throw in a autosports connector on the subharnesses (injector branch, coils etc) making for a modular design for upgrading, etc... that is something people would pay for.
but no one will would pay $700 - $800 for a new harness then pay you another $500+/- on top of that for crap plastic-jacketed cabling. it would be an overpriced harness.


If you are really looking for a replacement harness, try Neel @ ApexSpeed - I'm sure he can help you get in the right direction.

 

The problem is you can't buy the connectors, at all, ever, people have tried looking. I would have made a harness from the ground up for myself already if this was possible.

 

What connectors are you missing?

I built a harness for an SQ6 on my 3rotor, - I didn't have your luck, I was able to buy all the connectors needed.

 

was this new or used? New ones are what I'm after for an entire harness.

 

This would definitely be awesome and worthwhile. I'd definitely buy a custom made harness.

 

well once I have no job in a few weeks I will look into this more thoroughly.

 

update?

 

still have a job, lol. I may end up going to junk yards and getting some connectors out of 90's mazdas, hopefully I can get just about everything. I would imagine the OMP connector would be impossible. I would also put fresh new pins in the connectors.