Ben's Z Posted April 22, 2013 Share Posted April 22, 2013 A local Z buddy and I got may some headway today on the harness, even without the ignition harness I accidentally chucked at the coil. Looking at both the wiring diagrams from the sticky, the one provided by cygnusx1 and the more colored elaborate one I have a couple of questions. 1) When we had to make the harness that is comprised of the dotted line on the tutorial we did the following. I cut off the unused female "T" plug from underneath the dash on the zxt harness to use on the ignitor. We soldered on a connection to the distributor WITHOUT a condensor (must have got tossed). (Will it run without this?) We than continued on and used the opposite side plug on "Plug 3" of the tutorial. (We didn't cut off the plugs as seen in the sticky thread, instead we chose to use the plugs) We didn't know if that wire coming from the distributor and ignitor should be spliced to the zxt male plug/plug3 B/W wire then to the ignition or if the ignition needs to be between the two? 2) I ran my green fuel pump relay wire through an existing hole in the body harness grommet below the battery tray into the cockpit and underneath the plastic door trim. The previous owner has a fuel pump kill switch behind the passenger seat. Should I just tap into these wires for the relay, or actually send it out to the pump itself? I also mounted and grounded the fuel pump relay to the screw holding in the passenger washer nozzle squirter to the fire wall. Will this work? 3) We ran a single blue wire from the negative coil through through the speedo gear hole to go to the tach. For the life of me I cannot see anything on my back looking up behind the gauges. How hard is it to reach the tach, and what needs to be done the plug that in? 4) "Plug 1" BR and G, are these mounted to the + battery post? I took them out of the black zxt box they were housed in and still have the spade connectors on them. Do I need any other wires from that black box? Quote Link to comment Share on other sites More sharing options...
cgsheen Posted April 22, 2013 Share Posted April 22, 2013 (edited) 4. Ya... Sort of... In the ZX there's a positive battery connection to that black box (the fusable link holder). The Fusable Links connect to that, the Br & G wires connect to the Fusable Links. Personally, I used the black box - left the sockets for the two ECCS fusable links and the Br & G wires in place (mounted the black box to my firewall) and just spliced the +12V "feed" wire into the positive side wiring on the battery. (Or, get a circular electrical connector of an appropriate size and connect it to the starter - same place the positive battery connection is attached) But, the point is: Positive side of battery --> fusable link (or fuse) --> Br wire |__ --> fusable link (or fuse) --> G wire 3. Get under the passenger side of the dash. Find the square (rectangular really) Tach Resistor - It'll be just outside the taped up dash harness (so a person can change it). It doesn't look like a resistor at all - it looks like a small plastic box with 2 wires coming out one side. The signal from the Ignitor needs to go through the resistor before it goes to the Tach. Find which of the wires come from the engine bay (there will be 2 wires attached to the resistor). Cut the wire that comes from the engine bay and replace it with the new blue wire you just pulled through the firewall. Voila! Tach signal... 2. My advice: Run the power feed from the fuel pump relay straight to the fuel pump. Let the ECU and only the ECU control the fuel pump operation. On my Z, that just meant hooking the feed from the relay to the existing pump wiring right there in the passenger footwell. I'd advise getting rid of any other modifications to the pump wiring. 1. I don't know that I quite understand what you did with what would normally be the condenser and it's wiring between the coil and distributor... But: - The engine will run without the condenser. - If you don't have a condenser, there's no reason to connect the wiring to the distributor - The condenser is to help eliminate electrical noise - helping the ECU "hear" what the sensors are telling it without a lot noise getting in the way. Get one when you can and install it & wire it up to the dist. - until then, don't worry about not having one and don't make that wiring connection! (IIRC one side of the condenser is attached to the +12v IGN signal at the coil and the other goes to GND on the distributor body. You don't want a wire between those two points without the condenser in between!) On the Coil/Ignitor harness. It doesn't matter where you pick up the +12V IGN ON (BW wire) - spliced in near the IGN switch - OR whether you use the one your old coil used. It just needs battery voltage (no ballast resistor) at IGN ON. (I spliced it in near the IGN switch because I had the ZX coil/ignitor harness all bundled up so I took all that wiring through the firewall and made connections under the driver dash. It also made it simple to trace and I knew exactly where my coil power was coming from...) Edited April 22, 2013 by cgsheen Quote Link to comment Share on other sites More sharing options...
Ben's Z Posted April 22, 2013 Author Share Posted April 22, 2013 Thanks for the response. I should have noted this is a 1983 harness and I believe you did your swap with a 1981. Does this change things? Quote Link to comment Share on other sites More sharing options...
Ben's Z Posted April 22, 2013 Author Share Posted April 22, 2013 I am a little confused on the cygnusx1 notes on the wire to Pin 16 on the ECU. Shouldn't that pin be taken by the ecu pigtails? How are you splicing into that? Quote Link to comment Share on other sites More sharing options...
cgsheen Posted April 22, 2013 Share Posted April 22, 2013 Thanks for the response. I should have noted this is a 1983 harness and I believe you did your swap with a 1981. Does this change things? Nope. And, just so you know, I've done multiple swaps (other cars, not just mine) - used both types of harnesses. Currently I'm using neither - my "new" engine management is from a 1990 Infiniti M30... Quote Link to comment Share on other sites More sharing options...
cgsheen Posted April 22, 2013 Share Posted April 22, 2013 I am a little confused on the cygnusx1 notes on the wire to Pin 16 on the ECU. Shouldn't that pin be taken by the ecu pigtails? How are you splicing into that? This diagram in the FSM shows the EFI and Fuel Pump Relay in simple terms. Doesn't need to be more complicated than that. Pin 16 on the ECU is "the trigger" for the relay. It's the Lr (Blue/Red) wire from pin 16 to the 6-pin "connector 3" on the stock ZXT harness. Do this however suits your wiring setup: Blue/Red from pin 16 connects to the fuel pump relay coil. The other side of the relay coil goes to GND. IIRC "connector 3" in the ZXT ends up near the battery (or firewall penetrations on the passenger side) - and that's where I put mine. That's near where my fuel pump relay is, so it's a short hop from connector 3 to the relay. Doesn't matter, you just need to run a wire between pin 16 on the ECU to the coil on the fuel pump relay... Quote Link to comment Share on other sites More sharing options...
Ben's Z Posted April 23, 2013 Author Share Posted April 23, 2013 (edited) 4. Ya... Sort of... In the ZX there's a positive battery connection to that black box (the fusable link holder). The Fusable Links connect to that, the Br & G wires connect to the Fusable Links. Personally, I used the black box - left the sockets for the two ECCS fusable links and the Br & G wires in place (mounted the black box to my firewall) and just spliced the +12V "feed" wire into the positive side wiring on the battery. (Or, get a circular electrical connector of an appropriate size and connect it to the starter - same place the positive battery connection is attached) I took both spade from the brown and green and cut them off putting on one ring terminal for both and connected it to the positive on the battery... But, the point is: Positive side of battery --> fusable link (or fuse) --> Br wire |__ --> fusable link (or fuse) --> G wire 3. Get under the passenger side of the dash. Find the square (rectangular really) Tach Resistor - It'll be just outside the taped up dash harness (so a person can change it). It doesn't look like a resistor at all - it looks like a small plastic box with 2 wires coming out one side. The signal from the Ignitor needs to go through the resistor before it goes to the Tach. Find which of the wires come from the engine bay (there will be 2 wires attached to the resistor). Cut the wire that comes from the engine bay and replace it with the new blue wire you just pulled through the firewall. Voila! Tach signal... I think i found this. It had one blue wire and blue wire with a white stripe. I took a chance and cut the striped wire. I took both cut end and put them in a 14 ga. female spade and took my wire from the - on the coil and put on a male spade and connected the two. I hope what you were referring to was black and a rubbery plastic that had end that pulled off revealing a male and female bullets on either side.... 2. My advice: Run the power feed from the fuel pump relay straight to the fuel pump. Let the ECU and only the ECU control the fuel pump operation. I see a green and black wire running behind the passenger seat, both have shielded bullet connections. Which one do I splice in to and do I simply unplug that one and plug in my new one or is one of the existing wires still needed? On my Z, that just meant hooking the feed from the relay to the existing pump wiring right there in the passenger footwell. I'd advise getting rid of any other modifications to the pump wiring. 1. I don't know that I quite understand what you did with what would normally be the condenser and it's wiring between the coil and distributor... But: - The engine will run without the condenser. - If you don't have a condenser, there's no reason to connect the wiring to the distributor - The condenser is to help eliminate electrical noise - helping the ECU "hear" what the sensors are telling it without a lot noise getting in the way. Okay I took this female spade connector off of the distributor until I get this part... Get one when you can and install it & wire it up to the dist. - until then, don't worry about not having one and don't make that wiring connection! (IIRC one side of the condenser is attached to the +12v IGN signal at the coil and the other goes to GND on the distributor body. You don't want a wire between those two points without the condenser in between!) On the Coil/Ignitor harness. It doesn't matter where you pick up the +12V IGN ON (BW wire) - spliced in near the IGN switch - OR whether you use the one your old coil used. It just needs battery voltage (no ballast resistor) at IGN ON. (I spliced it in near the IGN switch because I had the ZX coil/ignitor harness all bundled up so I took all that wiring through the firewall and made connections under the driver dash. It also made it simple to trace and I knew exactly where my coil power was coming from...) Haven't got to this yet. Edited April 23, 2013 by Ben's Z Quote Link to comment Share on other sites More sharing options...
cgsheen Posted April 23, 2013 Share Posted April 23, 2013 I think i found this. It had one blue wire and blue wire with a white stripe. I took a chance and cut the striped wire. I took both cut end and put them in a 14 ga. female spade and took my wire from the - on the coil and put on a male spade and connected the two. I hope what you were referring to was black and a rubbery plastic that had end that pulled off revealing a male and female bullets on either side.... You should put up pics then we'd be sure, but I'm pretty sure you found the Tach resistor. I think you got the wrong wire though. Did you look at the FSM for your '77? Pretty sure the Blue comes from the coil and the Blue/white goes to the Tach. (yup - just looked at the FSM (Body Electrical, page 31)... Connect your new blue wire to the blue wire on the resistor and reconnect the blue/white, it goes to the tach.) So, wiring goes like this: Blue (from "-" side of coil) --> blue on resistor --> resistor --> blue/white out of resistor --> tach. Quote Link to comment Share on other sites More sharing options...
Ben's Z Posted April 24, 2013 Author Share Posted April 24, 2013 (edited) Ok I'm confused again. On the diagrams provided by cygnusx1 and the colored one, but specifically cygnusx1's are his plugs supposed to be looked at from where it plugs in or is that the view of wires going in to the plugs??? Because i see on the other schematic plug 2, black wire is grounded but I have green grounded because on the Cygnus schematic green is where black is on the colored one for plug 2 Edited April 24, 2013 by Ben's Z Quote Link to comment Share on other sites More sharing options...
Ben's Z Posted April 25, 2013 Author Share Posted April 25, 2013 Does this sound right.... I ran the B/W wire from the ignition relay from the passenger engine bay through the body harness grommet on the passenger fire wall over the transmission tunnel and soldered it and the homemade wire from the ignitor to the center spot B/W wire at the ignition switch. Bueller? Let me riddle this. Previous owner had cut the red and white wire in the steering column ran a jumper to the red and white on the ignition plug and then ran a wire from that to the positive on the battery.... I took it all out and put it back to original. He also had a universal relay with 4 wires going into 1 wire on the ignition harness for what I believe is the fuel pump anti theft switch. No idea about the wire to the battery+ Quote Link to comment Share on other sites More sharing options...
Ben's Z Posted April 25, 2013 Author Share Posted April 25, 2013 fuelpumprelay.jpg This diagram in the FSM shows the EFI and Fuel Pump Relay in simple terms. Doesn't need to be more complicated than that. Pin 16 on the ECU is "the trigger" for the relay. It's the Lr (Blue/Red) wire from pin 16 to the 6-pin "connector 3" on the stock ZXT harness. Do this however suits your wiring setup: Blue/Red from pin 16 connects to the fuel pump relay coil. The other side of the relay coil goes to GND. IIRC "connector 3" in the ZXT ends up near the battery (or firewall penetrations on the passenger side) - and that's where I put mine. That's near where my fuel pump relay is, so it's a short hop from connector 3 to the relay. Doesn't matter, you just need to run a wire between pin 16 on the ECU to the coil on the fuel pump relay... I am still a little confused on this. The blue and red wire comes out of the relay and plugs in to the 6 pin connector on the harness, then that same color wire dissappears into the abyss in the efi harness. There is no "end" to the wire as the diagram shows above. I didn't cut off my 6 pin connector on the harness side. Quote Link to comment Share on other sites More sharing options...
Ben's Z Posted April 25, 2013 Author Share Posted April 25, 2013 Well I cranked the engine tonight, and it turned over. Still don't have the pin 16 eccs to efi relay hooked up yet. I'm not sure if I should be too happy about the engine spinning over, not sure which percentage of the battle that is. I disconnected the green wire behind the passenger seat and put a new female bullet on my wire from my fuel pump relay and plugged it in. I left the old green wire coming from the front of the car just laying there. Quote Link to comment Share on other sites More sharing options...
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