ThirdEyeHatch Posted February 17, 2009 Share Posted February 17, 2009 (edited) Well I didn't know if I should start a new thread or post in a old one, so if I should post to an older one just let me know and ill have this one deleted. Any way I have the whole harness just don't know where to start. I didn't have time to mark wires when I pulled the harness, should I start at the ecu plugs and work my way out on stripping the harness? Couple of other things im not too sure about are, if the speedo in my 82 gl hatch has a vss built in, if the tach will support the signal from the ecu, if that gold looking ecu thing in the picture is the transmition computer, and if the auto ecu will work ok. The engine and harness came out of a 91 auto awd legacy btw. And I seem to have forgoten to remove the igniter, so if anyone has one for sale or a picture of what one looks like so I could get one for the junk yard that would be awsome. Edited February 17, 2009 by ThirdEyeHatch Link to comment Share on other sites More sharing options...
Numbchux Posted February 17, 2009 Share Posted February 17, 2009 well, you're in for a heck of a project if you didn't mark the plugs. that was my biggest hold up on my first one.....now it isn't too much of a problem, because I recognize all the plugs. yes, the computer with the 4 black plugs is the TCU. the ECUs are the same, just a signal wire that tells it whether it's in an AT or MT car. once you cut off this wire, it'll switch over. the tach signal will work just fine. I'm not sure if it'll have a reed switch or not. I've heard that some EA81s do, but I know Phizinza had to fabricate one for his brat. I've also only ever heard of one person running an OBD I EJ22 that needed a VSS, and that was Phizinza, so that might be an oz-specific thing. the smallcar.com website specifically states that it is not needed in OBD I cars..... BUT, I'll give you a couple pointers. first off, start with plugs you know you WON'T be using. and remember, a cut wire is a cut wire, they behave the same no matter where you cut it. so, don't just grab a connector you know you won't be using and cut it off. if you know you won't be needing it, trace each wire back into the harness as far as you possibly can, and THEN cut it. if you trace it back into the harness, and it splits, cut it before the split as you might need that wire elsewhere. if you come back to it, and you've cut off all the other wires, then you can move past it. if any of them lead to a plug you know you'll be keeping (ECU, specifically), look it up before you cut it. you might not need it, but it's always good to double-check. great ECU pinout for looking up individual wires here alright, now, un-do the SMJ (huge grey plug with the bolt through it) and seperate the part of the harness that went up through the fender (has one ECU plug on it, the underhood fuse box, and headlights/rad fans/etc.) and set this part aside. now lay the rest out like it was in the car. now, start from the passenger side footwell (where the cruise box was, this is the other computer with the 2 relays on it in the lower right of your pic). follow that entire harness across until you get to where it splits off and went through the firewall (this is where the MAF, crank and cam sensors, 02, and ignitor wiring is). of that entire clump of wires between there and the cruise box, you will only need one wire, which is the large BR (black with red stripe) wire, this is for the fuse pump. so cut that wire off at the plug at the farthest end from the relay, and pull it out. now trace the rest of those wires the other way into the harness and start cutting them off. you will not need ANY of them, just remember, if you come to a split, cut it before the split. next easiest is the TCU. again, you won't need any of these, but again, be very careful to cut BEFORE any of these splits, as it does get a signal from the TPS and a few others that are crucial to engine functionality. then to the fuse box (interior one) plugs. trace them each individually. most of these will not be used either, but the relays get their power here, so watch out for those. then to the couple plugs at the gauge cluster. you'll need to save a few of these wires, but again, most of them can go. *watch out for 2 wires here, they do not go to the ECU, but straight to the engine harness. one's GW and the other WG. these are for oil light and water temp signals* that's about as much help as I can offer. hope that gets you started. Link to comment Share on other sites More sharing options...
s'ko Posted February 17, 2009 Share Posted February 17, 2009 another tip is to make a couple of copies of the wiring diagrams. That way you will always have backups should coffee spill on them. :-\ Get masking tape and a sharpee and mark wires like tach or 10amp or whatever. For the connectors, I would find out what they were on the diagram and mark it with a number on the diagram and then take the tape and mark it with tape on the connector. It's also easier to deal with if you seperate the wires into main branches. The Air flow sensor, o2 sensor can be branched out so can the ignition and fuel relays. Cutting a wire and resoldering it to get it routed cleaner also helps when you are ready to get it installed. Most importantly, make sure that you mark the wires coming from the ECU. Those are the most important thing you need to worry about. Regarding the VSS I was able to tap into the reed sensor that you spoke of. I am not sure if there was a need, but it work and I don't have a CEL. This is on an EJ18 OBDI good luck Link to comment Share on other sites More sharing options...
ThirdEyeHatch Posted February 17, 2009 Author Share Posted February 17, 2009 Hey thanks alot guys. What is a reed switch? Link to comment Share on other sites More sharing options...
Numbchux Posted February 17, 2009 Share Posted February 17, 2009 VSS....the EA diagrams refer to it as the reed switch in the gauge cluster. Link to comment Share on other sites More sharing options...
Zefy Posted February 18, 2009 Share Posted February 18, 2009 some tips that helped me do mine. seems obvious, but make sure you have enough room to open up the harness fully. if you start folding over wires it can get confusing and cluttered. i also plugged in everything i needed to keep. intake, maf, alt, ecu, etc. Then i looked at the bits that weren't connected to anything then cut them. this narrows it down to only a handfull of wires that you need save separately. Link to comment Share on other sites More sharing options...
subaruguru Posted February 18, 2009 Share Posted February 18, 2009 i kinda did what zefy did but i marked engine things and then plugged stuff from in the car into the harness and removed what i didnt need heater controls,blower motor,trans ect. Link to comment Share on other sites More sharing options...
XT6 Magic Posted February 18, 2009 Share Posted February 18, 2009 Also, if you hook everything up and ground it properly you should be able to mock it all up on the bench. When I did my EA81 SPFI harness I had spark, injector pulse, fuel pump power, and the ability to set trouble codes ect all running on the bench before installing anything in the car. Link to comment Share on other sites More sharing options...
ThirdEyeHatch Posted February 19, 2009 Author Share Posted February 19, 2009 Does any one know what the select monitor signal is for? Link to comment Share on other sites More sharing options...
The Scooby Posted February 19, 2009 Share Posted February 19, 2009 the select monitor was a reader basically that plugged into that connector and acted like the newer OBD2 code reader. you could see parameters and such to help diagnose problems. id just leave it in. Link to comment Share on other sites More sharing options...
ThirdEyeHatch Posted February 20, 2009 Author Share Posted February 20, 2009 Hey thanks I think I almost have it done just a couple of plugs left that I have no idea where they go. Ill post some pics and see if you guys could identify them. Link to comment Share on other sites More sharing options...
The Scooby Posted February 20, 2009 Share Posted February 20, 2009 or bring it by my place/work, now that my wagon runs with the EJ swap we can compare them. Link to comment Share on other sites More sharing options...
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