Guys,

Just a short question... May be a YES or NO would work...

Q: If I take out the whole Body / Dash / Door / Interior Electric Harness... Leaving just the Engine Harness going to the ECU. Would the engine start if I wire correctly the Starter ??

I know may be the electric Fans won´t work, but would the engine start ??

Or there´s something needed in the body harness that won´t let me start the engine ??

Am building a race car and am SO afraid to take every harness out to rewire just what I need...!!!

Please your kind feedback...

Thanks..!!

 

To put it simply, no. There are a few X connectors that daisychain power to the ECU and ignition. If you're building a 'race car' going with a standalone ECU and wiring from jump will be your best bet.

 

Standalone is ideal but I would keep wiring intact just to simplify things even if its a racecar.

 

Wut? How is keeping the wiring harness simplifying things in a purpose built race car?

 

there's a couple wires besides the engine harness that need to be connected to the ecu, they are the wires coming from the blue 14 pin body plug that hangs out under the dash and plugs into the blue connector on the harness; apart from the ecu. This provides power to the injectors and a few other necessary components. Without this, all the necessary sensors will still be connected to the ecu, but they won't receive power.

I just swapped a 13brew into an FB using the stock FD ecu and FB body harness. I wired each wire to the ecu directly...theres a lot of stuff that is unnecessary to make an fd run. Only two of the plugs on the back of the ecu are utilized, and a few on that blue 14 pin connector to make it run.

 

For what you sound like you want to do with the car, I would just gut out what you dont need, and leave the stock wiring loom in there. Even if half the loom is not plugged into anything, as long as the important plugs are there- IE injectors, etc to make it run, that would be all you need.

On the other hand, if you were to take the entire wiring loom out of the car, I would just run a standalone ECU like Microtech/Haltech/whateverTech and use a universal loom. But thats a bit of work. Different plugs on things need to be matched up to the loom, etc.. I've done that and its not my favorite job.

 

Ok,

So I guess the best option is to run a standalone ECU and custom wiring the ECU to the engine sensors and electronic.

Q1: If it´s done like that can I take EVERY harness out of the car and re wire just waht I need ??
Q2: Would a plug and play standalone ECU (PFC, Adaptronic) and custom build harness work for that purpose ??

Am building a full purpose race car and would like to re wire the body to a much more simple setup...

Thanks

 

You need to download the FD wiring diagram shop manual and look at the ECU pin and the body harnesses.

Make a list of whats necessary to make the engine run and trace each wire from the ECU to these sensors, and trace the power/ground to each sensor.

Study the ECU pinout. You'll notice that 50% of the wiring the make the car run is already part of the engine harness which already plugs directly into the ECU via two yellow connectors.

Whats left is going to be map sensor, ignitor wiring, clutch switch, neutral switch, stoplight switch, map sensor wires, ecu main power, ecu switched power, and a few others. Some of these sensors have more than just one wire that runs to the ecu pins. Likely additional wires will be power/grnd for the sensor. You need to make sure that whatever is not already hooked up to the ECU via the two engine harness yellow connectors, receives power and has a connection to the ECU and/or the blue 14pin connector.

If you have power to all the necessary sensors, and you have input to the ECU from these sensors, then the engine would run outside you car.


As far as buying a standalone, its the same boat. You'll still need to make sure the standalone gets all of its necessary signals from the required sensors; and if you toss your body harness you'll need to make sure the sensors have power/ground. The advantage of the standalone is that the standalone may not need as many sensors to run properly so less hassle. Also, with a standalone, you may be able to troubleshoot faster as you'll be able to see on a laptop what inputs are working.

Conclusively, you CAN make the engine run perfectly fine without the body harnesses if you research which sensors are going to need power/ground and signal to the ECU.

 

Check with Ruler Mark. I know he is one of the owners on this forum that has done a FULL rewire.

 

Thanks for taking the time to answer.

I goota say I was expecting a simple YES as an answer... I´ve seen MANY different build threads where they take every inch of wire for painting or building a full purpose car... And I always thought in case of race car they would just rewire the body with what´s needed and the ECU would take car of the engine...

So, may be I should reformulate the question...

If all 3 connectors for a PnP ECU are wired and actually connected to the sensors or "device" the engine should start ??

I can take care of following every single wire attached to the 3 connectors at the ECU and make sure is plugged and working... But I don´t think I´ll do that on every harness of the car...

I´ll contact Ruler Mark.... Gracias..!!

 

It will start if all the "3 connectors for a PNP ECU are wired", but only if you have taken care of that 14 pin blue connector on the harness which connects to the main body harness as this is where the power to the injectors comes from etc...



My answer seems complex, however during my swap, I had all the sensors hooked up to the ECU and the car would turn over and spark but no fuel. Wasn't until I discovered that the blue connector APART from the ECU had to be wired up to its respective sensors.

 

Again, if this is a race car it'll be easier, cleaner and cheaper (time) to run a standalone.

 

If it's a race car I would just re-wire, it's easier than you think. I thought re-wiring the whole car was over my head until I found the right people to make the new custom system for me. It was as easy as making a list of everything I want to run and he built it in a couple weeks, provided the new wires and detailed diagrams of what needs to connect to what. Check out my build thread to see my fuse/relay panel, switch panel, etc.

 

You'd be better off rewiring the car and using a stand alone EMS imo.

If you also need side lights, brake lights, dash cluster working etc etc. Then just thin down the original harness and modify/beef up where required.

Its not as bad of job as it sounds, I actually quite enjoyed rewiring my car.

 

If you're not particularly attached to a plug and play - and a frazzled crappy old engine harness - there are a few wallet lightening devices available to save about 80% of the 26kg of the wire in these things. Motec does their PDM and MSD/Haltech smartwire. I hear there's a megasquirt style, cheap possibility coming too, but more aimed to the formula car market where you don't have to worry about most of the BS on a former road car.

 

The igniter / coils run from the Front engine harness not the motor's harness so those need to be there in order for the motor to start .If you went with a microtech it uses its own indevidual harness , and coil packs I believe .

and what kind of racing are you doing , because the TNS relay for the rear tail lights is in the front harness so.. if you do not need any kinda lights ok , but if you do need lights you would need to A rewire everything to run the lights or B keep the stock wiring .

 

Am actually building my car for local Time Attack competition, so I need all the Lights to be working....

What stand alone ECU would you recommend for its wiring and tuning simplicity on 13B ??

Also CEYLON, do you have any thread about the rewiring you did ??

Thanks,,,!!

 

If you need your lights et cetera to function...you're basically going to need every harness unless you're willing to rewire the entire car. It sounds to me like you're not building an actual race car.

 

You'll need to blue connector as stated before. We have our one racecar running a Power FC in a fully gutted chassis that's been completely rewired. I'll see if I can get some pictures with the wiring exposed...

 

Mono4lamar

That´s exactly what I need..!!! So I guess is doable...

All I have to do is make sure the blue connector from the ECU to body harness is connected to averything is supposed to ?? And then it should start ??

Thanks..!!

 

If you want to use a full wire in model and do it yourself, you can use the Adaptronic E440D Select( Same functions as the FD Plug and Play, just not setup for OMP or stick twin control). We can also supply a fully terminated engine wiring harness also. You could then pair it with a race technologies dash for instrumentation, and wire the rest of the lights yourself( pain-less wiring makes a simple setup). There are many ways to go about it.

 

Elliott,

Would you please PM a quotation for the E440D Select ECU & Harness ??

No Air Pump/ No OMP / No AC / No PS / Single GT35R / Stock Primaries / ID2000 Secondaries / AEM Coils (not there yet but thinking about getting them) / Aftermarket Electric Fan /Stock Themosensor

Thanks...

CC