im doin a s5 t2 swap in my s4 na and im stuck with the wiring at the moment due to the s4 under dash harness plug bein different to the s5 t2 ecu. what do you guy suggest? is there a link thats helpful? i try searching for awhile and found nothin so decided to post a thread.

 

you're gonna have to look at the wiring diagrams for each and splice the harnesses

 

yup get the diagrams and schematics out and cut and solder or splice (whichever) but either way you will have to hardwire the s4 dash harness into the s5 t2 ecu. OR you can buy a S4 t2 ecu and use your s4 NA wiring harness and just run the s5t2 motor off the s4t2 ecu, either way you will have to put in more time and money.

 

https://www.rx7club.com/forum/showthread.php?t=721283

 

https://www.rx7club.com/forum/showth...ight=FC3Sdrift

If your using a JDM harness that was meant for the right hand drive cars, you will not find the wiper or cruise wires in the JDM harness and you'll have to overcome that by using those wires from your n/a harness. IF I understand how things work, the JDM harness will be missing a large orange plug that exists on the USA EM harness. That missing plug is the one that carrys the wiper/cruise/other misc wires.

It's doable, but you have to have patience and some understanding of how the FSM wiring diagrams work. It's not a plug and play. Effort is involved.

And FC3Sdrift is having problems with his right now. It seems it's not his wiring, but the N374 ECU that came with his JDM engine. Beware of the N374 ECU or at least cautious about using one.

 

I went from S4 to S5 TII and in the end changed the entire harness (JDM - UK) this was mainly due to the engine harness, dash harness and also even the door plug connections were different so just changed the lot. Splicing is the quick and easy way but i changed the whole lot in a day and cost me about $80. I also at the same time checked and rewrapped every inch of it as the engine harness can go very brittle. Also the door connectors corrode. If you do it this way then you will have to get all the various relays and harness ECu's as they are different. S5 does seem to have less components.

 

Digi7ech is the local pro on these matters. send him a PM

 

I MEANT to post this thread: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s4-na-s5-jdm-turbo-conversion-405617/page2/

But I accidentaly pasted the wrong one in my first reply. Sorry 'bout that.

 

FC3Sdrift, I found this old thread: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/jspec-wiring-diagram-pleasee-n374-help-518542/

Go to the bottom of the first page and read his solution. Which is: http://www.mts.net/~chipsale/

Still, I would have sworn I read a thread sometime that mentioned how the pinnout was different on the N374.

In fact a fellow named ang71cat in another post suggested such. You might PM him but I think he sold his car?? Mabe.