Why worry about the harness???

[JeffS]

Well... being an electrical engineer, I was not too concerned about dieting my harness. But after looking over the schematics I have to admit that this diagram gave me the willies...

22494

[Mechie3]

Haha. Thats my favorite pic to show people.

"What are you doing?"
"This"
"What the!?!?"

I colored it in with markers to identify what i need and dont need since some of my tagging reads "module near brake lever".

[wleehendrick]

But after looking over the schematics I have to admit that this diagram gave me the willies...

Seriously... I have a Ph.D. in Electrical Engineering and I am dreading digging into the harness!

[wallace18]

I actualy did my harness 6 months ago but still went for Waynes ECU/Harness. Much better setup IMO and worth the money to me. I may do my own version of his setup in the future builds for customers. Basically mates a aftermarket Ron Francis style harness to the factory one and ECU. Very clever setup. Much more simple fuse boxes and relay setup. Wayne did a nice job. I had to fix a few wiring issues that may be specific to my car year vs data Wayne had. It was no big deal at all. I was an Electrical /Instrumentation Technician for 21 years.

[flynntuna]

I actualy did my harness 6 months ago but still went for Waynes ECU/Harness. Much better setup IMO and worth the money to me. I may do my own version of his setup in the future builds for customers. Basically mates a aftermarket Ron Francis style harness to the factory one and ECU. Very clever setup. Much more simple fuse boxes and relay setup. Wayne did a nice job. I had to fix a few wiring issues that may be specific to my car year vs data Wayne had. It was no big deal at all. I was an Electrical /Instrumentation Technician for 21 years.


Are you saying that Wayne is selling the engine ECU, engine harness and body harness for the 818 as a complete replacement for the donor harness? If so even me with electrical phobia may be able to get thru this hurdle.

[wallace18]

Are you saying that Wayne is selling the engine ECU, engine harness and body harness for the 818 as a complete replacement for the donor harness? If so even me with electrical phobia may be able to get thru this hurdle.

That is correct! It is well worth it IMO. They used it on the GRM build as well.

[nkw8181]

hmmm more info please

Nolan

[tirod]

There's another alternative that is being used - the mulitplex CAN bus systems. The most well known is ISIS. It uses a smart controller that receives inputs, and signals the remotely located power distribution box to operate that circuit.

Left turn signal wire grounds, the controller commands the front and rear power boxes to blink the left bulbs in the programmed sequence, and you get blinking lights. One wire for that to the controller, controller communicates to the boxes thru coax cable, the boxes get power by a 10 ga supply and send voltage out to the bulb to ground.

It wires up in less than 60% of the time of a traditional harness, only has signal and power leads where needed, and weighs substantially less than a factory harness. Depending on the quality of wire, nonetheless, it's all new, not 20 year old donor wiring thats been extracted and reinstalled with all it's faults and voltage drop issues from age. It also much easier to diagnose an error, and interactive with the MOSFET switchers than signal when there's no connection.

It's a body harness and doesn't interrelate with an ECU harness at all. But that's the point with a Subaru.

CAN bus systems are factory on larger emergency vehicles, the street rod community (who hates wiring and who invented the one wire alternator ) are using it in a lot of cars now. The Roadster and Coupe guys have no issues with it, and it's being used on older muscle car protouring rebuilds.

FWIW.

[John H]

I'm sorry but $2,100 for the wiring harness is too pricey for me.

[WRX Dave]

Is anyone working on a trimmed down harness to work with the factory ECU?

[Silvertop]

Is anyone working on a trimmed down harness to work with the factory ECU?

I don't know the answer to that -- but I do know that a significant problem to pursuing that is that there is no single factory ECU. They vary from year to year and from turbocharged vs NA. I'm guessing that there would have to be at least a half-dozen (maybe more) trimmed-down harnesses to cover the bases.

[Mechie3]

Not only do they vary year to year, turbocharged to NA, but they vary based upon body style and options (such as sunroof, heated mirror, seats, type of HVAC). Granted, those are mostly non ECU inputs, but part of the body harness. a lot of things are cross wired though. It'd be more cost effective for someone to offer a "ship me your harness, I ship it to you fixed" service.

[C.Plavan]

Not only do they vary year to year, turbocharged to NA, but they vary based upon body style and options (such as sunroof, heated mirror, seats, type of HVAC). Granted, those are mostly non ECU inputs, but part of the body harness. a lot of things are cross wired though. It'd be more cost effective for someone to offer a "ship me your harness, I ship it to you fixed" service.

I would pay.... no doubt. I WISH someone would do this with a factory harness.

[WRX Dave]

I would pay.... no doubt. I WISH someone would do this with a factory harness.
I would pay for that service as well. Electrical is the one part of this build that I'm dreading.

[Scargo]

Since I'm doing a racer I ask myself, "how hard can the wiring be?" Granted, I've wired custom cars before and created a loom fixture (yes, a 4x8 sheet of plywood and finishing nails), and made harnesses. What gives me the willies is finding or choosing the connectors and pins. Particularly where they connect to existing components like the ECM. I suppose I could even do a new engine connector since my wiring will be so pared-down or use terminal blocks. Thing is, I do not intend to solder or use barrel crimp connectors if I can help it.
How do the lights come? I'm assuming the headlights have connectors. Do you get the mating connector and loose pins or are they designed to connect to a Subaru headlight connector?

So, where do you get connectors and pins? Where are the diagrams and charts that define how to describe and identify connectors? There seem to be a million variants. I'll confess, besides running across them on Amazon I've really not researched this much.
I know that many, if not most, pins can be removed and replaced if you make the right tool and/or are ingenious. That would be a stroke of luck if pins could be replaced... I've had varying degrees of success with my half-*** attempts to remove and reuse them in the past.
Is there an online presence that caters to kit car builders for wiring? Something more professional than Radio Shack? Does Subaru offer blank connectors and pins? Has this been discussed ad nauseum on another forum? I'm so in the dark as to what will be coming with the car.

[tirod]

Weatherpak pin removers are commonly available tools for mechanics these days. You can get them online or thru an auto parts store.

Solder vs crimp has it's fans on either side. Military spec is crimp - done right. The reason is that a soldered connection typically has a much stiffer section of wire near the connector where it wicks up the filaments during the application. The military has found in high vibration severe duty use, it fails. Military connectors have to be able to disconnect much more than the typical 10 times weatherpaks are rated, because ongoing maintenance of other assemblies over a 20 year lifespan require it.

Here's more about how that applies to high end race cars: http://www.rbracing-rsr.com/wiring_ecu.html

What we need to worry more about is keeping moisture from creeping into the harness and corroding it. That's the #1 killer of wiring harnesses, and the #1 reason flood damaged cars are sent to salvage - mechanically they just need an oil change, electrically, they need a complete harness change. It's not economically feasible to swap out the harness on most cars, the cost is too high in labor alone.

Building a new harness with tinned wire to resist corrosion, high disconnect rate plugs, and the liberal use of shrink tubing or self sealing wrap would get the typical auto harness out of the bargain basement level of construction. The auto industry ranks lower than a motorboat in that regard - really - the boat has to use good watertight switches with no exposed conductors anywhere. A car? Don't use more than garden hose pressure to clean it or you will drive water into the connectors which will leave you stranded. Happens at the car wash, or to those who think a 4WD is impervious to anything. They soon learn differently.

This is precisely why the CAN bus controller are worth the money for a chassis harness - a two power box system runs $1200. It doesn't address the engine controller, though, because they are always proprietary. We wind up reusing or sourcing the connectors at the ECU and sensors because we have to - but it doesn't mean we have to run the same low cost choice wiring. Computers use a lot of 5VDC sensors that make the circuit 2X more sensitive to voltage drop - many send signals in .1VDC increments to the computer. With voltage drop losses over 1 volt per meter in old wiring, it makes a hash out of how the computer calculates injection. Garbage in, garbage out.

A quality injection harness is your first priority - what pistons or crank it uses means nothing if the data is junk and it won't run right. It's not your grandpa's Buick anymore, wiring it much more important with EFI than many understand. Let's not forget, tho - what the manufacturer has to do with making a wiring harness is constrained by the requirement of a 50,000 mile emissions warranty, and their need to sell you another car a few short years after that. They aren't in the business of making bulletproof wiring harnesses, just one good enough to get them past a statutory requirement.

[Mechie3]

I would pay.... no doubt. I WISH someone would do this with a factory harness.


I would pay for that service as well. Electrical is the one part of this build that I'm dreading.

Just in case you're wondering....

I have no plans or desire to do this. :lol:


Since I'm doing a racer I ask myself, "how hard can the wiring be?" Granted, I've wired custom cars before and created a loom fixture (yes, a 4x8 sheet of plywood and finishing nails), and made harnesses. What gives me the willies is finding or choosing the connectors and pins. Particularly where they connect to existing components like the ECM. I suppose I could even do a new engine connector since my wiring will be so pared-down or use terminal blocks. Thing is, I do not intend to solder or use barrel crimp connectors if I can help it.
How do the lights come? I'm assuming the headlights have connectors. Do you get the mating connector and loose pins or are they designed to connect to a Subaru headlight connector?

So, where do you get connectors and pins? Where are the diagrams and charts that define how to describe and identify connectors? There seem to be a million variants. I'll confess, besides running across them on Amazon I've really not researched this much.
I know that many, if not most, pins can be removed and replaced if you make the right tool and/or are ingenious. That would be a stroke of luck if pins could be replaced... I've had varying degrees of success with my half-*** attempts to remove and reuse them in the past.
Is there an online presence that caters to kit car builders for wiring? Something more professional than Radio Shack? Does Subaru offer blank connectors and pins? Has this been discussed ad nauseum on another forum? I'm so in the dark as to what will be coming with the car.

I've removed pins all almost every connector in the car using just a very small jewelers flat head screwdriver. If you're doing a pure race car, it's probably easier (though more expensive) to make your own harness. All you need are the ECU inputs and a power distribution block. Most street cars won't make their own harness because you want to retain things like lights, cruise control, blinkers, wipers, and other OEM functionality.

[Scargo]

Good stuff tirod (http://thefactoryfiveforum.com/member.php?7073-tirod). That one link... http://www.rbracing-rsr.com/wiring_ecu.html was amazing! A goldmine!
Within it, that one link to Prowireusa connectors (http://www.prowireusa.com/c-2-connectors.aspx) is the kind of thing I am looking for.

EDIT: Now I know Weather Pack and Deutsch connectors and more. Still had a helluva time removing squarish female pins from the multiple piece Delphi/Tyco-Amp style connectors on the harness.
Is anyone using wire better than TXL (like teflon coated [Tefzel] or better)? Found good pricing at skygeek.com (http://www.skygeek.com/mil-w-22759-16-unshielded-tefzel-aircraft-wire.html).

[WRX Dave]

Just in case you're wondering....

I have no plans or desire to do this. :lol:



I've removed pins all almost every connector in the car using just a very small jewelers flat head screwdriver. If you're doing a pure race car, it's probably easier (though more expensive) to make your own harness. All you need are the ECU inputs and a power distribution block. Most street cars won't make their own harness because you want to retain things like lights, cruise control, blinkers, wipers, and other OEM functionality.
I might go with the race car harness for engine functions, then run a separate system for lighting, etc. like the ones used on kits cars with non-ecu engines.

Granted, my delivery isn't scheduled until October, so who knows what will come by then. I will say that if someone offers a service to send in my donor harness and get a ready to go 818 harness back, my checkbook will be ready. I like Wayne's harness, but I have 10 years of experience tinkering with the factory WRX ECU and I don't really want to learn a new system, not when anything I would ever do to the engine is well within the capacities of a reflash.

[C.Plavan]

Just in case you're wondering....

I have no plans or desire to do this. :lol:



I've removed pins all almost every connector in the car using just a very small jewelers flat head screwdriver. If you're doing a pure race car, it's probably easier (though more expensive) to make your own harness. All you need are the ECU inputs and a power distribution block. Most street cars won't make their own harness because you want to retain things like lights, cruise control, blinkers, wipers, and other OEM functionality.

I hope it is that simple for a race car. I'm guessing I will also need the Immobilizer, iginition with key with the ECU. I need to keep the OBD2 handy. I have both the front and under dash wiring. (motor harness is already wired up).

Am I forgetting anything else?

[Xusia]

On the subject of water and electrical corrosion...

I've owned 2 MGB convertibles with the AWESOME!!! (<--hopefully, you can fully appreciate the sarcasm inherent in this statement) Lucas electronics. One was 15 years old when I owned it, the other was 20. Needless to say, I've dealt with corroded wiring. And really - seriously folks - it's NOT THAT BAD! It takes a long time for normal moisture exposure to have an effect. But it should be duly noted here, neither car was ever submerged or flooded - THAT is different story and I would avoid the wiring such cars. But the corrosion caused by normal use and exposure to rain now and again is in my mind, inconsequential. There is moisture in the air, so unless you are using a special wiring harness made to resist all corrosion, you are going to have to deal with it at some point, and the fact the 818 is a convertible isn't going to measurably make this worse. Be smart about where you run your wires, and be smart about any electrical work you do to the harness. Dry your car out if you caught in the rain and get some accumulation inside. This goes a long way. And, if you store your car under some kind of cover, some of those larger silica packets are great.

In summary, unless you are the kind of truly serious idiot who routes wires along floor pans (TIP: Don't do that!), gets caught in down pours, and then lets that accumulated water sit (TIP: Don't do that! Dry it out!!), I really doubt you have much to worry about. But if you are THAT kind of idiot, please do NOT build your own car. Have Wayne do it for you! :)

[Wayne Presley]

I'm sorry but $2,100 for the wiring harness is too pricey for me.

Well that's $2100 with car harness, Electromotive ECU, crank trigger wheel and pick up, air temp sensor (so you can get temp readings after the intercooler instead of just ambient like the stock system), software and it weighs 14 lbs. You can put the harness in the car in less than 2 hours and have the car running. And its full programmable, runs your fuel pump, fans, boost control, shift lights, and an AIM/RaceLogic dashes via CAN (2 wires get all the info to the dash). The other side is you spend 20 + hours trimming down the stock harness, spend $650 on a Cobb tuner. How much is your time and aggravation worth?

[tirod]

That is exactly the point - you can put in the harness Wayne offers, or stumble thru a cut and paste mess with old donor wiring that was stripped none too gently out of a wreck.

Estimates of doing a Roadster donor harness vary, but most report 40 working hours in installation and troubleshooting. With a CAN bus system, the chassis gets done in about half, and there won't be much troubleshooting if any. Plus, it's new virgin wire with no corrosion to interfere with low voltage signals.

It's always a interesting contrast - plenty of owners can justify a stroker rotating assembly for $2,100, but a decent wiring harness that will be trouble free for the next 20 years isn't seen as a plus. However, chopping up a used one already 15 years old is ok. Turn that around - would you drop a 15 year old crank in that new Dart block, or use the front and rear bearings or clutch as is from a 125k donor?

Live and drive old cars, you learn better. My 23 year old Cherokee was mechanically in good shape - the electrics were the major source of problems when I sold it. Door lock solenoids and windows were all getting less than 10VDC from the factory harness, the volt meter factory wired in the dash showed 11VDC running with full accessories on, but fortunately was still getting 13.5 at the battery. At least the system kept it charged up.

You have no idea if your harness was affected as badly as mine - a local car never mudded, offroaded, or used for water crossings. Nobody here or at TOS ever suggests doing a voltage drop test to determine whether their harness is even worth the work. And yet, at the hint of trouble, everyone suggests tearing down a motor for new machine work to fix a minor problem.

We are engine and mechanic centric, and ignore the nervous system that must be functional, the wiring harness. No money for that, it's a necessary evil. Better to spend it on show rims and fast rubber. If it starts and runs, it's good.

In 25 years I'm betting the kit car you build today will have to get the 35+ year old harness torn out and replaced. That is exactly what has to happen to the '60s muscle cars to get them restored or up to protouring standards.

Might want to think about it.

[wleehendrick]

Might want to think about it.

Good points; I thought about Wayne's harness and ECU, but still plan to use the factory parts, and get a Cobb Accessport (the new features in the v3 are all I need to supplement the stock cluster). It sounds like you speak from experience building a roadster. In my case, my harness/ECU are only 6-7 years old, from a reliable Japanese car which spent it's short life in CA. Besides a little dirt, it's as good as new. This should be far easier to deal with, and much more reliable, than 15-20 year old electronics from a rust-belt Mustang that many roadster builders have to deal with. Every case is different; the donor condition and build budget are big factors. If my donor parts weren't so cleasn, I would really think about Wayne's harness. If it's anything like his shifter kit, I'm sure it's a complete, high-quality fairly priced system.

[wleehendrick]

How much is your time and aggravation worth?

Apparently not much, since I did decide to build a kit car in the first place!

[Xusia]

Very good points tirod. It's not always about the harness though. In my case, I want to use the factory ECU. I would buy a new harness if I could do so for a reasonable price. Wayne's won't work with the factory ECU, and the ISIS system is just too expensive. So I'm left with the 10-year old wiring harness from my donor, and I will do what I can to recondition it as I prep it. I have a fair amount of experience with automotive and motorcycle electrical systems and although I don't relish the work before me, I think the result will be very good overall. As good as Wayne's or the ISIS system? Probably not, but it should be good enough and it should also last for years.

[DruOdil]

I plan on going with Wayne's system. I just need to cut off the connectors to send to him. The dash is another bonus option.

[Brando]

I want to use Wayne's system but still be able to pass DMV requirements to make my R street legal (lights, blinkers, backup light ect). Is this feasible? Is there a solution to avoid the stock harness dieting and still pass inspection?

[Wayne Presley]

I want to use Wayne's system but still be able to pass DMV requirements to make my R street legal (lights, blinkers, backup light ect). Is this feasible? Is there a solution to avoid the stock harness dieting and still pass inspection?

Yes, you'll need the harness set up for a street car.

[WRX Dave]

Will the VCP harness work with the donor instrument cluster, or do you need to run a digital display with it?

[wallace18]

I am using this harness with my 2002WRX donor cluster.

[Cheistan]

Wayne,

Is there a specific reason you went with Electromotive? I was planning on doing the same exact setup but with ProEFI (a supra buddy swears by it... and so does hennessy). More expensive for sure (1800 for ecu alone), but I am trying to get the best CANBUS aftermarket ECU i can find. I've done some research but ive seen very few good comparisons between the different systems (AEM, MoTeC, etc). If you could weight in it would be much appreciated.

[Wayne Presley]

The Electromotive is a CANBUS ECU, the software is straight forward, the hardware is very reliable, the ECU has the circuit board coated, and the tech support is very good. The AEM, MoTec, Adaptronic, ProEFI are very good systems. I can get you any system you want and set it in the harness.

[Cheistan]

Wayne,

What electromotive ecu are you going with? Also do you not need a wideband o2 sensor ?

Thanks,

Chris

[mobius]

ProEFI has traction control built in right? what is the cost and that system with a harness as well as the electromotive system?