IMPORTANT UPDATE:If you used version 2.5 of this document to build your harness, please download version 2.6 now as there were a couple of errors that have been corrected in this version. Thanks. Version 2.6 has been tested from start to finish with superhatch on his car and proves completely functional after the corrections identified were made. Thanks Stephen for your feedback and being patient as we worked through the issues on the phone.

Hello Everyone,

This is my first post contributing versus consuming the fantastic information I find here on NICO. I had not found any document like the one I created so after countless hours of pouring over electrical schematics, multimetering physical connections and transcribing hand-written notes to put this all together I thought I would post it for public consumption.

The document on the link below is a complete cross reference (source->destination) of all the wiring conversion/integration necessary to get a VH45DE into a Z32. Many Nissans are wired in a similar fashion so others may find this document useful as well. This document is intended to be a starting point, so any suggestions on how to improve are always greatly appreciated! Think of it as a Request for Comments (RFC) at this stage.

I am hosting this document on my servers so any changes incorporated will be placed in that document. This way we can have a "single source of truth" versus an attachment that can become outdated.

Caveat: I am waiting for craigztoys (hint-hint) as he's fabbing up my engine mounts and oilpan. With that said the wiring harness has not been tested. Craigztoys is also reviewing this document against his conversion with a 90 motor and we'll make updates as feedback becomes available. I will do the same when the motor is in my Z.

I hope you find this document useful and maybe it can save you the hours of work I put into it!

Good Luck with your projects!

Nick.

http://www.b2b-now.com/vh45det...g.pdf

Modified by npez at 4:14 PM 10/14/2008

Modified by npez at 4:15 PM 10/14/2008

Modified by npez at 11:45 PM 1/2/2009
Modified by npez at 12:32 AM 1/31/2009

Nick, that's simply amazing!!!!

You get my vote for n00b of the year... Glad to have you aboard!!!

Thanx Nick. I went over it earlier, and looks all correct.I second the Noob of the year award.

Trust me guys, we have been chatting for a few weeks about this, he has a lot of time in the wiring. He did an amazing job. Soon there will be 2 450ZX's within a hundred or so miles. i fortell awsome videos in the future.

Again, Thanx nick.

Nick, Oh yeah, I like the disclaimer you threw in, and gotta say the how to read this, sure makes it easier to read. Thanx again for all the leg work.

Awesome work! There are a few mental notes I will add and these are all IIRC.

In the fsm's it lists 2 wires for the fpcu on the Z. My z only had 1. 90 na 2+2 Don't remember the color.

There are fan relay outputs from the Q ecu listed in the fsm. My 92 ecu did not have these. I believe infiniti added this feature to 94+. The early Q's have a thermoswitch in the radiators for fan activation.

Thank you everyone for your kind words.

Craig: Yeah I put the extra narrative at the top and notes, etc. on the bottom before posting the document as you and I have talked about this but it would be difficult for someone reading it for the first time. I fixed the typo on line C that you sent me (long nights) and will be posting the update v2.1 shortly. As for the disclaimer I had to put it in there because while the document makes it easier it's not meant to be a "how to re-wire your car for dummies" - like they say if it was easy everyone would be doing it!

T45: Thank you for the feedback. I had added a bit about the fuel pump on the normaly aspirated Zs but it's buried at the bottom under "notes" (maybe I'll bring it to the top) - I don't believe they used variable fuel pressure so they aren't equipped with that feature (it's actually shown as a whole different setup on the 11x17 wiring diagram supplement that I have). If I'm misunderstanding you let me know and I can update accordingly. As far as the Q45 is there anyway you can elaborate on the thermoswitch (wire color - basic diagram if possible and PM it to me) and I can incorporate this new information into the document (Giving you credit of course - I'm going to add a credits section to the doc).

Once again thanks to everyone.

Nick.

The thermo-switch is located in a port on the Q radiator. It is a 2 stage switch with the first stage closing or making contact at 190* F. The second stage closes well above 200. I'm not sure of the exact temp but it doesn't matter since most will want fans on at 190 and above.

There are 3 wires, IIRC they are blue, green and black. Black runs to ground and I think the blue was the 190 wire. I could be wrong, it's all from memory. To find out I simply put the switch on the stove in a pot of water with a thermometer. At 190 the black made contact with the other wire, blue. I think. lol It's all taped up and a real ***** to get to for a visual.

While I am typing this (sitting in my Z in the garage) I just hooked up consult. The plug by the ECU that runs to the Z contains the consult wires. I'm not sure if you have them yet but here they are. They are as follows.

Q ecu harness to Z plug

21-brown/yellow to blue22-yellow to white31-brown/white to orange

I haven't tested yet, need a serial-usb for my laptop but this should be correct. I'll keep everyone posted.

Thank you for the information. I'll update the spreadsheet when I get back home and post the information.....

Thanks Again,Nick.

The consult wires are correct. It seems to be working great.

Awesome document Nick. Regarding the thermo switch/fan issue. This would only be relevant if you plan to use the '94 16 bit ECU in your build. If you plan to use the 8 bit ECU from a pre '94 model which is easier to rechip and tune BTW, there wouldn't be wiring for that fan output. Even if you are using a '94-95 motor you could use the '93 ECU. The rechipped ECU in my '94 Q45 is from a '93.

qsiguy wrote:Awesome document Nick. Regarding the thermo switch/fan issue. This would only be relevant if you plan to use the '94 16 bit ECU in your build. If you plan to use the 8 bit ECU from a pre '94 model which is easier to rechip and tune BTW, there wouldn't be wiring for that fan output. Even if you are using a '94-95 motor you could use the '93 ECU. The rechipped ECU in my '94 Q45 is from a '93.

Shane,

Thanks Shane. and thank you for the additional info. Let me ask you a quick (multi-part )question. On the ECM swap to pre-94, is it a plug and play affair? For example are the 94-95 EFI harnesses pinout compatible on the pre-94 ECMs? Are the 94-95 sensors compatible with what the pre-94 ECM is expecting? Are there any benefits to staying 16bit versus going to 8bit?

Since you've already done it I thought you probably have gone through the rationalization of all of this. I've got a 94 motor/95 harness and both 94 and 95 ECMs. I can go over to my friend with the junkyard and swap one of the ECMs out for a 91 or 92 that he has.

Please advise.

Thanks,Nick.

npez wrote:Shane,

Thanks Shane. and thank you for the additional info. Let me ask you a quick (multi-part )question. On the ECM swap to pre-94, is it a plug and play affair? For example are the 94-95 EFI harnesses pinout compatible on the pre-94 ECMs? Are the 94-95 sensors compatible with what the pre-94 ECM is expecting? Are there any benefits to staying 16bit versus going to 8bit?

Since you've already done it I thought you probably have gone through the rationalization of all of this. I've got a 94 motor/95 harness and both 94 and 95 ECMs. I can go over to my friend with the junkyard and swap one of the ECMs out for a 91 or 92 that he has.

Please advise.

Thanks,Nick.

Nick,

The harness pinouts are the same, it is a plug-n-play affair.

Copy that...No modifications necessary. Only difference that anyone can find is the cooling fan output. Both the 8 bit and 16 bit ECU's are tunable but in my opinion the 8 bit is easier. The main EPROM chip is a standard 28 pin chip. Same chips most tuners use fits right in. There are also emulators that will plug right in for real time tuning. I'm not sure how it would work for your application but in a otherwise stock Q we try and find an ECU from a car that had the same options like TCS. I know you can turn off a "TCS Flag" within the ECU so maybe it won't matter in your application

Thanks Guys - I really do appreciate the input - it's good to know that the ECMs are plug and play. Let me ask you another question. On the 94 electrical diagrams IIRC it shows a radiator fan as well as the A/C condenser fan. Is the A/C condenser fan functionallity there on the pre-94 (I don't have a pre-94 electrical diagram) or is it part of the thermo-switch you mentioned? I would assume it had an electric condenser fan but I haven't seen a complete car

Also Shane,

Is there a portfolio of software/hardware tools you use that you would recommend as far as the tuning aspect of this? I'm somewhat of a noob when it comes to engine tuning though I have a general familiarity conceptually with fuel maps, timing maps, etc. and took some computer engineering classes during my undergrad work (this was ages ago though - maybe it'll come back and come in handy ).

Please advise and thanks a bunch again for your help guys....

Nick.

A/C condenser fan still works fine. It turns on with the A/C and I'm pretty certain I've noticed it turn on when the motor was hot and the a/c was off. Either way I've never had any overheating issues with the '93 ECU.

Components I use for tuning:

1)Tunerpro for editing the bin.

2)Burn1 hardware for burning the EPROMS. A Moates product. Flash n Burn software used for the burner.

3) ECUTalk I like for datalogs

4) Nissan Data Scan for map trace and some data logs. Also good for pulling your existing bin from an ECU.

5) Moates Ostrich 2. Don't have but I want it it is an EPROM emulator that takes place of the EPROM and allows tuning without swapping chips all the time. When used with EmUtility (free) it can allow for real time tuning. As soon as you save a bin file change EmUtility (available from the Tunerpro people) will send the new file to the Ostrich (or other emulator) even while the motor is running.

6) Nistune is also very cool but a little spendy. Allows real time tuning and map trace. These features can be done with the options above. I haven't used but it looks very cool.

7) And of course you will need a consult cable. Available from a few sources. BlaZt has one. I got mine from a NICO member, name is Jaime, can't remember his username but I'm sure I can find it. I think he also sells them on ebay. Think I paid about $70-80 IIRC.

8) Laptop

9) Wideband O2. I use the Zeitronics Zt2, I'm happy with it.

10) The chips/sockets are widely available. Moates, who sells the Burn1 and Ostrich, sells several types of sockets and chips. I like the 27SF512 which I believe is a very commonly used chip. You can write/erase/rewrite on them over and over again. I have a few of them but have been reusing the same two for dozens of tunes. While one is installed I'll make the desired changes, burn to a chip, open the ECU swap chips and do it again. This is why the Ostrich or other emulator would be awesome. Would save a ton of time.

qsiguy wrote:A/C condenser fan still works fine. It turns on with the A/C and I'm pretty certain I've noticed it turn on when the motor was hot and the a/c was off. Either way I've never had any overheating issues with the '93 ECU.

Shane,

Thanks a bunch for all the info - I'll start looking all the stuff up as far as the engine management. Most likely I'll want to go the rom emulator route for dynamic tuning

On the termo-switch is this what it looks like?

If so I guess I will need to tap into a coolant line, add a fitting and mount it (I'm using a Howe radiator which I don't believe has a port for it)? I think the wires complete the coil circuit on the relay so I should be able to recycle my rad/sub relays.

If T45's (Thanks for the info again) information is accurate then:- Black is ground - Blue is the ground side of the Low Speed relay coil- Green is the ground side of the High Speed relay coil

The rest of the relay pins remain the same on the Z. Basically instead of the ECM providing ground this thermo-switch is doing the job on pre-94.

If you see yours working differently than this, please let me know.

Thanks,Nick.

Das it. I plumbed mine into my drain port on the Z rad with an adapter but since I'm swapping radiators soon that's not going to work anymore. I'm not sure what I'm going to use but I think i'm going to use one of the adapter that goes into the upper rad hose and has a 1/4 npt for a t-switch. Either that or just put in a switch.

T45 wrote:Das it. I plumbed mine into my drain port on the Z rad with an adapter but since I'm swapping radiators soon that's not going to work anymore. I'm not sure what I'm going to use but I think i'm going to use one of the adapter that goes into the upper rad hose and has a 1/4 npt for a t-switch. Either that or just put in a switch.

Awesome! Thanks for the feedback.....

Nick.

Nick have you seen the coolant temp sensor adapters like this one?

http://store.summitracing.com/...43215

If your radiator doesn't have a threaded port for one it and you don't feel like welding a bung into one of the tanks this is another good option.

That's the kind of adapter I'm talking about. I'm unsure if the infiniti tswitch will fit in it though. I am going to be taking my rad out soon as well as the switch so I'll be able to tell for sure what wire is the low speed/high speed and get a measurement on the threads.

I am going to have to give the switch to my friend that's doing the supra swap, it's getting the Q45 radiator I believe. lol Gotta plug the hole back up.

I was planning on using the fan output on my '94 ECU but I never saw the fan switch to ON when connected through the Consult plug even at around 200*F water temp. When I wired up the relay I ended up wiring my trigger to turn the relay on into the fuel pump wire. It was easily accessible. The only downsides I can see are:

1) Extra strain on the alternator since it's always running the fan when it doesn't need to.2) Since the fuel pump comes on for 5 seconds before the engine is started so does the fan. The fan only draws less than 15 amps max so it shouldn't drain the battery. I can always pull the fuse if the battery is low and it isn't wanting to start. 3) Takes a little longer to warm up.

Works for me.

Iused one of those radiator T fittings a few years ago, with great success. I Like to use the Painless wiring cooling fan controller for my rad. it is like 80 from summit, comes on at 185, off at 170, fuse it, and give it fulltime power, and you are set, as long as the fans are big enough and so is the radiator.

Back to topic,

I got my wiring all soldered, and wrapped, de-pinned the connectors, got them through firewall, back together, connected, everything laid out nice, while engine was in place, test fitted everything, just need to extend oil pressure wire, and splice Q alt wire into Z harness, or swap connector.

Once I went through all of it again, and again, and you know, then, made sure it will never get cut into by accident easily. I want to move some wiring more, to keep away from my unwrapped headers. The heat should not be too bad, but rather be safe, been there done that, asked How The *** did that happen? too many times.Now that I found the right bolts, I can hopefully have it up and out this weekend. May have to take J30 to H town.

Did you use the Q harness or the Z harness? The ecu plug will fit through the firewall, it just takes a LOT of finesse and removal of the plastic cover. Took me about 15 minutes but I got it through. The Z plug broke in half when I took it out though but still plugged into the old ECU fine.

I cut the Z harness at the firewall, during removal, and on reassembly depinned the connector that goes inside, and first feed the ecu through, PITA, but I got it. All is good, bolts come tomorrow for my crank May start it tomoro for first time in 3 years. almost 4.

tmorgan4 wrote:Nick have you seen the coolant temp sensor adapters like this one?

http://store.summitracing.com/...43215

If your radiator doesn't have a threaded port for one it and you don't feel like welding a bung into one of the tanks this is another good option.

I hadn't seen it but that will be a great option! Thanks for locating and sharing this.

Nick.

tmorgan4 wrote:I was planning on using the fan output on my '94 ECU but I never saw the fan switch to ON when connected through the Consult plug even at around 200*F water temp. When I wired up the relay I ended up wiring my trigger to turn the relay on into the fuel pump wire. It was easily accessible. The only downsides I can see are:

1) Extra strain on the alternator since it's always running the fan when it doesn't need to.2) Since the fuel pump comes on for 5 seconds before the engine is started so does the fan. The fan only draws less than 15 amps max so it shouldn't drain the battery. I can always pull the fuse if the battery is low and it isn't wanting to start. 3) Takes a little longer to warm up.

Works for me.

That's interesting.... I haven't tried it, but as I'm going with a pre-94 ECU (for tuning purposes) I will most likely go with an aftermarket controller. Something to control the fan came with my SPAL fan based on the Z1 motorsports description, but since everything (fan, radiator, injectors, o-rings, etc.) are still in the box and I'm too lazy to take everything out and put everything back in afterwards, I guess I'll cross that bridge when I get to it.

As far as your work around, it's not perfect, but hey if it works for you and since you can live with the nuances of the workaround - I think that's great! You can still take what you have and wire in an additional relay that can be controlled by the factory 3-wire thermo-switch to get around the downsides you mentioned, but at this point that's optional since everything is working just like you have it....

Thanks again for sharing your experience with this....

Nick.

Craig,

You may also want to consider this wire loom wrap in addition to wrapping your header.

http://www.jegs.com/p/Thermo+T...11801

I'm most likely going to coat the headers but will also use this for wiring along the firewall as well as wiring along the frame rails. I'm thinking replacing the plastic loom with this should work nicely....

Just a thought...

Thanks,Nick.

In the next hour I will be posting version 2.3 of the wiring integration document. I have included Ben's and Shane's feedback on the thermo-switch and also corrected some of the wiring information as I found some errors while building mine.

An interesting thing I'm trying to sort out is the aux fans. Basically the challenge is that from the wiring diagrams it appears that the Q had 2 fans of which 1 was a 2 speed (dual windings). The Z on the other hand has 1 fan being a 2-speed on the TT. Looking further into the diagram there are some distinct differences between the Q and the Z's activation of the fans.

The Q has ECM pin 4 (thermo-switch on the pre-94s) providing relay coil ground for low speed on one fan. For high speed ECM pin 5 provides relay coil ground (thermo-switch in pre-94s) and activates the high speed winding on one fan and also activates the other fan. BTW this could be backwards as it's not indicated in the FSM which relay is high speed and which is low speed - so it could also be that one relay activates both fans on low speed and then activates the high speed winding on one fan for the second stage. The interesting thing is that in parrallel to pin 5 is the A/C pressure switch that can *also* provide ground (the other side of the switch is grounded) and activate the high speed relay.

Where it gets interesting is that on the Z the A/C pressure switch is not grounded and connectivity goes through this switch to ECM pin 9.

The simplest approach in my opinion will be to ground the other side of the Z's A/C pressure sensor to the chasis (it's by the drier in the nose) and retrofit so it works in similar fashion to the Q's setup.

I haven't updated this portion yet on the document until I try it. If it works as I expect I will document it and update the document.

Thanks,Nick.

Version 2.3 of the document is now available. It has some corrections and integration of the thermo-switch for pre-94 ECMs.

You will need Adobe Acrobat Reader (Free download) to open the PDF file.

http://www.b2b-now.com/vh45det...g.pdf

Thanks,Nick.

I think I have all of the wires worked out except for 2.

1. Has anyone used the cranking signal wire (it is the Black/Yellow wire in the M95 connector in the foot well) when hooking their wiring up? I don't see a destination on the Q45 harness.

2. The Yellow/Blue wire that the FSM on the Z calls neutral switch; is this the clutch interlock circuit (that's what it looks like)? It seems that when the switch is closed it goes to ground. On the Q there is a Park/Neutral Position relay with a Gray wire and a Blue wire. Do one of these wires need to be grounded to signify a Neutral or Park condition? I'm trying to determine the recipient wire to integrate the clutch interlock circuit with the Park/Neutral circuit and if that's the case it makes it easy.

If anyone has any insight to this, it would be greatly appreciated.

Thanks,Nick.