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 This way we can have a "single source of truth" versus an attachment that can become outdated.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
Post Title:
Posted by: AZhitman at 5:46 PM 5/7/2008
You get my vote for n00b of the year... Glad to have you aboard!!!
Post Title: Re: VH45DE to Z32 Complete Wiring Integration Document (npez)
Posted by: craigztoyz at 6:09 PM 5/7/2008
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.
Post Title: Re: VH45DE to Z32 Complete Wiring Integration Document
Posted by: craigztoyz at 7:28 PM 5/7/2008
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.
Post Title: Re: VH45DE to Z32 Complete Wiring Integration Document (npez)
Posted by: npez at 8:39 PM 5/7/2008
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.
Post Title:
Posted by: T45 at 5:48 PM 5/15/2008
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 blue
22-yellow to white
31-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.
Post Title: Re: (T45)
Posted by: npez at 10:55 AM 5/18/2008
Thanks Again,
Nick.
Post Title:
Posted by: T45 at 2:33 PM 5/18/2008
| Quote, originally posted by qsiguy » |
| 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. |
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.
Post Title: Re: (npez)
Posted by: SuperHatch at 12:52 PM 5/19/2008
| Quote, originally posted by npez » |
Shane, Thanks Shane. and thank you for the additional info. Let me ask you a quick (multi-part 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,
The harness pinouts are the same, it is a plug-n-play affair.
Post Title:
Posted by: qsiguy at 11:14 PM 5/19/2008

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.
Post Title:
Posted by: qsiguy at 1:15 AM 5/20/2008
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.
Post Title: Re: (qsiguy)
Posted by: npez at 9:35 AM 5/20/2008
| Quote, originally posted by qsiguy » |
| 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. |
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.
Post Title:
Posted by: T45 at 10:00 PM 5/20/2008
| Quote, originally posted by T45 » |
| 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. |
Nick.
Post Title: Re: (npez)
Posted by: tmorgan4 at 2:35 AM 5/21/2008
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.
Post Title:
Posted by: T45 at 4:30 AM 5/21/2008
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.
Post Title: Re: (T45)
Posted by: tmorgan4 at 4:57 AM 5/21/2008
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.
Post Title: Re: (T45)
Posted by: craigztoyz at 5:57 AM 5/21/2008
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.
Post Title:
Posted by: T45 at 7:03 PM 5/22/2008
May start it tomoro for first time in 3 years. almost 4.| Quote, originally posted by tmorgan4 » |
| 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. |
Nick.
Post Title: Re: (tmorgan4)
Posted by: npez at 8:35 AM 5/24/2008
| Quote, originally posted by tmorgan4 » |
| 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. Works for me. |
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.
Post Title: Re: (craigztoyz)
Posted by: npez at 10:41 AM 5/24/2008
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.
Post Title: Wiring information updates
Posted by: npez at 2:56 PM 5/26/2008
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.
Post Title: Version 2.3 available
Posted by: npez at 7:48 PM 5/26/2008
You will need Adobe Acrobat Reader (Free download) to open the PDF file.
http://www.b2b-now.com/vh45det...g.pdf
Thanks,
Nick.
Post Title: Cranking Signal Wire / Clutch Interlock Signal
Posted by: npez at 2:50 AM 5/27/2008
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.
Post Title: Re: Cranking Signal Wire / Clutch Interlock Signal (npez)
Posted by: T45 at 4:41 AM 5/27/2008
| Quote, originally posted by npez » |
| 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, |
I can't recall anything about the starting signal.
The interlock wire does not need to be connected to anything at all. I believe that if grounded it will not allow engine to start so hooking up to the clutch interlock is possible, however, even with the interlock wire disconnected the car will still not start with the clutch out. The clutch safety runs through the switch on the pedal before going to the start relay so it's already wired up to work fine with the vh ecu. Easiest to just leave the interlock alone.
The wire on the drivers fenderwell that's labeled neutral actually goes to the transmission to indicate neutral to the ecu to allow the IAC to keep the revs up in between shifts on the V6. Not sure if one can incorporate it into the vh ecu or not. It sounds cooler when the rpm's drop fast to me so I did away with that wire....and the iac too!
Post Title: Re: Cranking Signal Wire / Clutch Interlock Signal (T45)
Posted by: npez at 9:57 AM 5/27/2008

Thanks for the feedback Ben.
Nick.
Post Title: Re: VH45DE to Z32 Complete Wiring Integration Document (npez)
Posted by: craigztoyz at 2:32 PM 8/14/2008
WES,
METTLER,
can we get this Sticky'd Please. There is Critical knowledge in this document that we all need at one time or another. Thanx, Craig
Post Title: Re: VH45DE to Z32 Complete Wiring Integration Document (craigztoyz)
Posted by: LEMHEAD16 at 2:08 PM 10/14/2008
| Quote, originally posted by LEMHEAD16 » |
| Main link does not work anymore! Can we host it on NICO? |
Try it now though it all works.....
Thanks,
Nick.
Post Title: Re: (tmorgan4)
Posted by: Panther in a Q45a at 5:10 PM 10/14/2008
| Quote, originally posted by tmorgan4 » |
| 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. |
Long time since the original message, but here is a source that is more affordable.
http://cgi.ebay.com/ebaymotors...91561
Post Title: Re: (Panther in a Q45a)
Posted by: LEMHEAD16 at 10:52 PM 10/14/2008
Did not connect the 5v? sensor wire to anything, no problems
did redo all the grounds, and add extras, have not had any issues.
I have not had the EGR hooked up, or the air bypass valve, although the other engine I have has the complete intake and am going to use it on the dyno to see if there is a difference between with and without EGR/airbypass. Even with it cold in the mornings, it has not been an issue, runs good from startup, great after a minute. Idle is never an issue. the connectors are just chillin there taped over.
I did put in a major modification to the engines wiring harness, that allows me to run it in 4 cyl mode, giving me about 6mpg better, and still willl easily accerate on the freeway to pass people.
I will be having this as an option on my swaps, and the harnesses I sell.
If you get a large enough aluminum radiator, and have enough air in the front, you will rarely need the cooling fans to be on.
Hope my experience helps, Craig
Post Title: Re: VH45DE to Z32 Complete Wiring Integration Document (npez)
Posted by: SuperHatch at 5:58 AM 10/21/2008
| Quote, originally posted by npez » |
Link corrected. I can't host on iServe as it doesn't accept PDF! I can't send it to NICO as I need to also have access to it as if I receive comments/updates, I want to have 1 system of record so the changes to get mixed up. Try it now though it all works..... Thanks, |
Nick,
I'd be happy to host the PDF on my site. Just email any time you have an updated version and I'll change it within a day or so.
Post Title: Re: (craigztoyz)
Posted by: SuperHatch at 5:59 AM 10/21/2008
| Quote, originally posted by craigztoyz » |
| On the wiring, I did not hook up a starting signal. works great Did not connect the 5v? sensor wire to anything, no problems did redo all the grounds, and add extras, have not had any issues. I have not had the EGR hooked up, or the air bypass valve, although the other engine I have has the complete intake and am going to use it on the dyno to see if there is a difference between with and without EGR/airbypass. Even with it cold in the mornings, it has not been an issue, runs good from startup, great after a minute. Idle is never an issue. the connectors are just chillin there taped over. I did put in a major modification to the engines wiring harness, that allows me to run it in 4 cyl mode, giving me about 6mpg better, and still willl easily accerate on the freeway to pass people. Hope my experience helps, Craig |
Cut power to one of the power transistors?
Post Title:
Posted by: Carl H at 7:17 AM 10/21/2008
*edit*
here is a link discribing how chrystler did it, using electromechanical means...very cool stuff indeed.
http://www.allpar.com/mopar/new-mopar-hemi.html
Post Title: Re: VH45DE to Z32 Complete Wiring Integration Document (SuperHatch)
Posted by: npez at 7:48 AM 10/21/2008
| Quote, originally posted by SuperHatch » |
Nick, I'd be happy to host the PDF on my site. Just email any time you have an updated version and I'll change it within a day or so. |
Thanks again,
Nick.
Post Title: Re: (Carl H)
Posted by: SuperHatch at 6:23 AM 10/22/2008
| Quote, originally posted by Carl H » |
| i'd imagine it would consist of killing off 4 of the injectors, else it would bore wash the hell out of the engine. also how are you going to deal with engine wear...this was a problem on the older cadilacs (i think) that had primitive displacement on demand...it would cut off the same 4 cylinders and it would wear the engine prematurely due to the pistons still acting as an air pump and not having combustion press the rings against the wall; bores got torn up and thus engines worn. *edit* |
Thats exactly what I was getting at. The injectors are all powered off of the same power source, so putting in a simple switch to cut power to 4 isn't "simple" but can be done without too much trouble. The PTUs are powered independently but like you said, cutting power to one will wash out half the rings over time, not to mention the harmonics issues since this engine, as with most V8s, doesnt fire even-odd-even-odd.
I can't think of any other wiring harness mod that involves adding a switch that will randomly deactivate cylinders, but I guess I'm missing something.
Post Title:
Posted by: Carl H at 9:21 AM 10/22/2008
I can't download the pdf anymore
Want's a password...
Fix or e-mail please?
Chris.
Post Title: Re: (Chrispy300)
Posted by: npez at 9:47 PM 1/2/2009
| Quote, originally posted by Chrispy300 » |
| Bumpity! I can't download the pdf anymore Fix or e-mail please? Chris. |
Thanks & Happy New Year,
Nick.
Post Title: Re: (npez)
Posted by: Chrispy300 at 1:08 AM 1/3/2009
If your ever in Aus I'll shout you a beer or 10
Post Title: Re: (npez)
Posted by: SuperHatch at 5:05 AM 1/3/2009
Thanks again for this, I'll be taking a good look at it this week!
Post Title: Re:
Posted by: npez at 9:31 AM 1/3/2009

Nick.
Post Title: Re: Re: (npez)
Posted by: SuperHatch at 11:16 AM 1/3/2009
| Quote, originally posted by npez » |
Thanks guys - I'm glad it helps out.... Steve got your voicemail and plan to call you back over the weekend - currently wrapping up a home remodel which has gone over by 2 weeks ![]() Nick. |
No problem, no rush. I'm just trying to straighten out my PS setup and had a couple questions on the wiring. Besides that I'm almost up and running.
Post Title: Re: Update
Posted by: npez at 10:35 PM 1/30/2009
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