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NA to turbo wiring harness
Posted: Tue Nov 13, 2007 6:47 am
by stipro
I just want to know if I can keep the ecu side of the wiring harness to convert NA automatic to turbo 5spd. I know the engine side has to be changed for the extra sensors, but was unsure about the stuff onder the dash. Can I just put a turbo 5spd ecu in aswell to the factory wiring??
Posted: Wed Nov 14, 2007 5:12 am
by beatersubi
I can't speak to the change in transmission, but I know that you can re-use the entire n/a harness. You simply have to swap a few pins at the ECU connections and add the wiring for the boost related sensors/solenoid.
All the info is here if you search. I did and found what I needed.
Posted: Thu Nov 15, 2007 1:34 am
by stipro
beatersubi wrote:I can't speak to the change in transmission, but I know that you can re-use the entire n/a harness. You simply have to swap a few pins at the ECU connections and add the wiring for the boost related sensors/solenoid.
All the info is here if you search. I did and found what I needed.
Yeah I looked around but didnt find exactly what I have needed yet. Thanks for the additional info though

Re: NA to turbo wiring harness
Posted: Mon Dec 03, 2007 5:04 am
by vrg3
Your car's harness doesn't have pins in the ECU connectors to mate up with many of the pins you need to connect to. Just like how it doesn't have connectors in the engine bay to mate up with some of the sensors and solenoids you need to connect to.
So, what I'd recommend is just running new wires from the ECU all the way out to the engine bay for each of the new connections. You'll need to add contacts to the ECU harness connectors; I'd suggest sourcing them from a junkyard.
Josh did this conversion (though I don't know if he did the wiring in this way); his car used to be a front-wheel-drive non-turbo automatic, and now it's an all-wheel-drive turbo manual. Knowing how thorough he is, I'd guess that he's posted all the information you need either on the BBS or on his web site.
Posted: Mon Dec 03, 2007 7:51 pm
by Legacy777
The engine harness is the same.
The only sensors that need to be added are the boost related sensors on the passenger strut tower. Just run those as a separate bundle of wires back to the ECU, and pin them back to the ECU connectors.
You also have to swap the positive leads for the crank & cam sensors.
I have not done a write-up for my engine swap, so those details aren't on my site, but are floating around on the BBS.
Re: NA to turbo wiring harness
Posted: Thu Jun 21, 2012 3:29 pm
by cj91legss
I have a quick question about doing this. My turbo legacy has a 91 turbo wiring harness in it. I'm replacing the harness within the next couple days, I have an N/A 91 Harness. At the engine harness they both have the same 3 square connectors. Do I need to make any alterations to the N/A engine harness connectors before I plug them into the turbo engine harness connectors?
Re: NA to turbo wiring harness
Posted: Thu Jun 21, 2012 5:25 pm
by PhyrraM
IIRC, yes you would have to repin a few things.
The easiest is to put a N/A engine harness on your turbo motor. Then it should plug in and all you would need to do is the ECU connectors and add the boost sensor and Solinoid.
Re: NA to turbo wiring harness
Posted: Thu Jun 21, 2012 5:59 pm
by cj91legss
That's not what I wanted to read.....
Re: NA to turbo wiring harness
Posted: Thu Jun 21, 2012 6:32 pm
by Legacy777
If they're the same square type, they may have the same pins, but I'd have to look at the 91 FSM I have at home to verify.
Shoot me a pm or email to remind me and I'll try and look tonight.
Re: NA to turbo wiring harness
Posted: Thu Jun 21, 2012 6:41 pm
by cj91legss
Yeah they're the same, even visually. At a brief glance, it also appears wire colors are the same. I will shoot you a pm.
Re: NA to turbo wiring harness
Posted: Thu Jun 21, 2012 6:49 pm
by Legacy777
91 may have been the "butter" year where they were both the same. I'll check this evening and let you know.
Re: NA to turbo wiring harness
Posted: Fri Jun 22, 2012 2:22 am
by Legacy777
That 3rd connector, F27 is all grounds, so there should be no reason you have to swap harnesses if it plugs in.
In fact, if someone wanted to, they could probably depin the round connector and use the rectangular one if they had the patience to do all that
