MJLamberson Posted September 18, 2008 Share Posted September 18, 2008 So looking at my wiring harness from a 83zxt, and looking at my wiring harness from the 77... Im lost. To be specific: Does the ignition harness plug Into the main harness before the ECU or are one of those three connections to the ECU for the ignition? I really havnt touched the ignition harness before so I dont know what it looks like or what Im looking for. The only right ups I can find are from the 81 harness, which I guess has enough differences to confuse the typical guy? Does anybody know of any place or thread based off an 83 wiring harness for use in an s30? With pics? I need pics! Im sorry for the lame post guys but Im feeling overwhelmed right now and in need of guidance. Quote Link to comment Share on other sites More sharing options...
MikeZcar Posted September 21, 2008 Share Posted September 21, 2008 Have no experience in this but maybe this will get your post more attention. The search function didn't help? Quote Link to comment Share on other sites More sharing options...
MJLamberson Posted September 21, 2008 Author Share Posted September 21, 2008 I really wasnt expecting anything to come of this thread, I am just getting frustrated with this wiring. Thanks for the bump though Quote Link to comment Share on other sites More sharing options...
Tony D Posted September 21, 2008 Share Posted September 21, 2008 There are basically six pins on the ZXT harness that you need to attend to, and if you have the wiring harness diagram for the 77 you can see places to hook them up to. Some wires either need to be piggybacked for alternative uses if you are not using the whole featured items from the harness (like FICD Valves, etc...) or having a sub harness made to handle the ignition output to the coil/ignitor connection. You could use that portion of the 83 harness, but it's a PITA to excise out of the body harness of the 83 and transfer it. The pins I refer to are the wires that go to EFI relay, Fuel Pump Relay, Power, Ignition and maybe two others (Ignition trigger and Ignition Signal In to ECCS). That's all you need to physically connect of the ZX harness to any application that isn't already hooked up to a sensor, component, or box that you took out of the ZX when you parted it. You ARE using just the ECCS bits from the 83 correct? You're not transferring whe whole wiring harness and trying to make it work, right? If you look at the diagram of the Haynes Manual specified in the L28ET to 240 post that seems to be really popular, it shows the connectors and gives wiring purposes for them. The control logic of the combined EFI and Fuel Pump relay on the 77 is slightly different than on the ZX, but basically you can use an old 77 wiring harness to 'pigtail' the connections from the 83ZXT harness into, and PLUG RIGHT INTO the 77 body harness to make a sanitary no alterations to the 77 wiring harness hookup. You will have to run the ignition trigger wire (yellow or yellow with white trace if I recall) but there really is nothing you need to hack in the 77 to make the setup work. This is the connector from the EFI system that plugs into the main body harness up under the steering column. White, with I think six connectors in it. Plus a single white one on a blue wire that I will talk about later. You just have to pin out the harness properly in the correct connector and plug it in. Randy 77ZT showed me that on his car YEARS ago, and for some reason once I saw that, it was like "OH!" and from there since it knew it could be done, it happened. Unfortunately, right now, I'm like 6000+ miles from any notes or access to photos that would be remotely helpful to you with this. All I can say is 'it's easier to convert a 75-78 than it is to do any 240 or 260! All the wiring is there, you just need to interface like 4-6 wires, and run two more (for the ignitor). Hell, the tach even works! Oh, for a more direct answer to your question: The three plugs into the ECU from the ECCS harness are out to the sensors(inputs and outputs). Basically they are grouped at power/grounds, sensors, and injection harness for fuel injectors. There is a single white spade connector in the main body harness of the ZX that hooks to a mating single spade connector on the ECCS harness---this is where the ECU gets the ignition pulse signal for RPM and Initiation of the injectors (the CAS only gives ignition signals so the ECU can send the trigger pulse to the ignitor, the coil MUST fire for the ECU to sense the coil is working and the engine running to fire the injectors.) This single spade connector DOES go to a pin in one of the three connectors, (input connector' if you want to name it, but it's a separate connection that comes directly from coil negative as an input to the ECCS (and EFI) Computer. Luckily, in the 77, you ALREADY have that wire in the main harness, and it hooks up similarly in the EFI harness there. Then again, that may be one of the two wires I'm thinking you have to run, but I may be wrong. I think the wire is blue and comes directly from the Coil Negative. Same singel white plastic spade connector in both the Z and ZX, and they plug right in. Quote Link to comment Share on other sites More sharing options...
MJLamberson Posted September 22, 2008 Author Share Posted September 22, 2008 Im not sure I fully understood you there but thank you very much for taking the time to try to help me... Are you saying that I can leave the 77 harness all hooked up and plug it into the ZXT harness By connecting those pins from the 77 harness to the appropriate pins on the connections to the 83zxt? That almost sounds to simple? Quote Link to comment Share on other sites More sharing options...
smoorhs02 Posted September 22, 2008 Share Posted September 22, 2008 i am going through this same thing, except with a 78. i bought a 83 280zxt 2+2 automatic that was wrecked and am in the process of pulling the harness. what did you do when you got your harness...in regards to the wires/connectors that go right near the battery and back towards the cabin, but inside the fender(not sure if thats the right term)im not going to cut anything, and am wondering if im going to have to get up under the passengerside dash to disconnect something. im searching this topic right now, actually how i came across this post. maybe we can help each other Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted September 22, 2008 Share Posted September 22, 2008 Where is that crappy diagram I made while I was upside down under the dashboard with my right hand using a left handed pencil? http://album.hybridz.org/data/500/TurboZ-WiringDiagram-DRAFT-1.jpg Not sure if it's ANY help at all but even if it gives you ONE little tiny bit of insight, it was worth posting. Quote Link to comment Share on other sites More sharing options...
ozzinc Posted September 22, 2008 Share Posted September 22, 2008 I have a 83 turbo wiring harness, and the 3 connector plugs go to the ecu, then there is the small din 6 pin config plug that goes to the distributor that has the built in crank trigger diode, if you have the distributor from the 280zxt then you will see where that small din plug connects to the distributor. and if you have the 83 ecu you will see where those 3 plugs connect right up to the ecu, I hope this info help. Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted September 22, 2008 Share Posted September 22, 2008 Can't help you at all with your question/problem but I can suggest one of these, they come in very handy when you are on your back under the dash. You can pick one up from Dixieline Lumber for less than $20. I have used several different types in my daily work and this style is by far the best and of course you have both hands free. They are generaly called "head lights" and this model uses two AA batteries and last for about 40 hours before requiring new batteries. Dragonfly Quote Link to comment Share on other sites More sharing options...
smoorhs02 Posted September 22, 2008 Share Posted September 22, 2008 cygnusx, the part of your diagram labeled 'mostly prewired FIrelay'...is that part of the 83zxt harness? over near the battery? or up under the dash? it does help me understand how to work this problem some more...thank you. and ps...its NOT crappy!!! lol jeremy Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted September 22, 2008 Share Posted September 22, 2008 cygnusx, the part of your diagram labeled 'mostly prewired FIrelay'...is that part of the 83zxt harness? over near the battery? or up under the dash? it does help me understand how to work this problem some more...thank you. and ps...its NOT crappy!!! loljeremy Yes, that relay was pretty much already wired into the ZXT harness in the ZX it was all up by the battery/fusible link box. I triggered the relay from the IGN+ on the coil post (labeled new wire) but you can do that from any switched 12V source. The fuel pump relay in my diagram is not completely wired. If you notice, it's missing a switched 12v+. I don't know why I didn't document that. It was either already wired into the ZX harness or I missed it. I did use the ZX Fuel Pump Control Module initially. Eventually, the Walbro Pump killed the ZX Module and I just used a switched 12V+ to turn on the fuel pump. This is not ideal because if the car wrecks, the pump will keep pumping fuel. I think the AFM has a switch in it to shut the fuel pump off if the flapper shuts (engine off). My memory is getting dimmer. I did take some photos so look around at the photos. http://dcerutti.smugmug.com/gallery/1749234_5BA2m#87164467_Y92Cy Quote Link to comment Share on other sites More sharing options...
smoorhs02 Posted September 23, 2008 Share Posted September 23, 2008 memory getting dimmer...hmmmm....lol thanks for the info and pics! yea, keepin the fuel pump going after a wreck would definetly be a bad thing...at least youre remembering the important parts! safety first. MJ is this helping you out? Jeremy Quote Link to comment Share on other sites More sharing options...
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