bakwoods

@KiwiRS4T Turns out it's the active spoiler plug. Apparently the Type M had an active spoiler which was wired back to the chassis harness which had that one yellow plug directly above the ECU. I'll throw a picture on for good measure tomorrow. However after speaking to my two Skyline friends (both R32 guys) they said there's was blank. Someone speculated it was A/T related however it's not. Glad to get that out of the way. Meanwhile, see other thread for updates. I still need help from ANYONE WITH AN A/T SKYLINE GTS-T!!!!!

Update: The brown and black wire go to the inhibitor switch. If you look at the picture uploaded, it's the plug on the bottom of the fuse box. For those doing the M/T swap you'll know that you can merely bridge this connector with a single wire and two space connectors. It'll allow you to start the car. For us slush box guys, the same principle applies. Though frankly, every wire should have a home in my opinion. The other plug I discovered is the gear selector. I'm still yet to find any sort of TCM pin out nor is there anyone who's even cut the plug off and dissected it, however what I do know is that you can use the male end (chassis side) to tap into the reverse lights. From what I've read it's a red wire and a green with white stripe wire which are for reverse. All that's left is to deduce what the other wires are. Similarly, I looked closer under the car, there's a shielded cable with a red and white wire coming off of it. Previous owner cut it back and tied in another wire to the shielding wire. Not sure what the purpose was, if anyone has any clue it'd be helpful. Also....what the hell is the 3 wire plug on the fuse box go to and what does the brown plug go to?! It's driving me nuts!

Minor progress has been made. Old chassis harness was part # 24010-03U10 (CA18i motor) and the new GTS-T harness is part #24014-01U11 (RB20DET motor). If it's any consolation, if anyone needs to look up part numbers for their harnesses use the following link: http://jp-carparts.com/nissan/carlist.php?maker=nissan

I've included some pictures of the cut wiring. The moron prior snipped the connectors off and hard wired a lot of things. I wish I had taken a look before undoing this. Unfortunately it was so jacked up that nothing matched. To add insult to injury, the new chassis harness and the old chassis harness TCM plug wiring colors are different. They were both A/T so I'm assuming different year or different trim? The new chassis harness supports more things my old one didn't (EGT probe) and some power options. I've identified the brown + black wire as going to a connector and I fortunately had a spare pigtail I can make work that fits the bottom plug on the fuse box. Though I still have the 3 sets of wires. I'm assuming they're 7 pin, 7 pin, 3 pin. There's terminals on the fuse box for just that. If someone would be kind enough to check under the hood, trim back some of the wire and just take a picture of all three plugs from the transmission side going in so I can see what wires go to what pins. I still need a pigtail for a 7 pin plug which is missing. I wonder if it's possible to convert a male pin plug to female?

PM'd

Damn I was going to take off your hands! Grrr what a steal. BTW PM'd

Like the title says, ISO wiring diagram for the A/T R32 4 speed. I can't seem to find one anywhere. Since I can't find the harness, I'm going to see if I can just snip some connectors off of my old chassis harness and re-pin them for the various wires. If anyone's got a lead on the diagram that'd be amazing. Also, can someone throw up a picture of their fuse box? There's 4 plugs on the side for the autos, I want to see what plugs go where. I'm assuming 3 plugs are for the transmission inputs since there's 3 sets of wires, the other plug I'm assuming is either alternator or something else? Thanks!

The early twin cam engines featured the NICS system, while the later twin cam engines used ECCS. I read that the Fairlady 200ZR was fitted with an intercooled NICS type RB20DET, I suspect that the engine and harness came from a 200ZR then perhaps? Would explain the R31 ECU?

Not me, I just listed on eBay and then on here separately. Looking to unload my R31 ECU and get the blue connector RB20DET one.

Hahaha, yeah it's R32 Skyline, FR chassis. I suspect it was a GXi with the original CA motor which got yanked out and the idiot who installed the motor set just happened to have an RB20DET floating around from something that was powered by the R31 ECU. No idea what model used that ECU but the circuit board seemed to work fine with it. Then again, that's why I invested in new wiring from the chassis to the engine and now trying to find a trans harness. I put up a FS thread to rid myself of that ECU and try to secure the correct one. If I ever sell the car, I wouldn't feel right selling something that was so poorly retrofitted. If I show you pictures you'd die laughing. Imagine butt connectors, BUTT CONNECTORS EVERYWHERE.

Hey guys, looking to buy (relatively inexpensive if possible lol) an RB20DET automatic ECU. I can't locate one online and the majority that come up end up not being compatible because they're listed wrong and the serial number is for a manual. Any help is appreciated. I can't find any support in the US. I'mean certain that someone has one or even can go to a pick and pull and get their hands on one. As well need a trans harness for my car. I suspect that the Z32 NA harness will work because it's the same part number transfer though...won't leave to chance. Similarly, instead of starting a new thread, I got an R31 A/T ECU which was used on my R32 by previous owner, ugh. If anyone wants or needs I'll be happy to help out. Maybe we can do an even exchange.

My idea of expensive is $200 or more which seems to be all I can find if I'm lucky. Plenty of RB25DET but no RB20DET. I'm keeping the 20DET for now until I do the Neo swap. Honestly I have no idea lol. The car ran on the R31 shockingly well, but there was quite a bit of hard wiring involved to make it run. Even so, RPM's were totally off, I mean wayyy off. Speedo wasn't reading correctly but otherwise it wasn't meant to even have the SMIC it turns out. The chassis was an FR, so I'd figured out it was a GXi sedan with a fair bit of work. The car changed hands a few times. I suspect it was the previous owner from Russia.

Hey guys, need some help trying to figure out what the plug is on my chassis/engine harness next to the ECU, the three engine plugs have a home but there'sone plug on the chassis harness that is missing a home. Anyone with an auto RB20DET if you could reply to this and tell me if you've got it plugged into something. I'll upload a picture tomorrow morning, it's nearly 11pm here and it's too dark to see anything. It'd be nice if it's just an optional plug as my old chassis harness was ripped to shreds and had an R31 ECU hard wired in.

Good morning all. I figured I might as well start a build thread on my 1990 Skyline GTS-T (Gxi hybrid). The backstory of this car is pretty out there. It's an FR chassis, had a motor swap done on it, the previous owner cut the engine harness and hard wired an R31 ECU and hard wired the TCM as well. Needless to say it was less than attractive. Fast forward to yesterday. We just finished installing the chassis, engine and alternator harnesses. I was fortunate enough to find the harnesses on eBay via international sellers. For >$500 I was able to secure those. I'm still missing a transmission harness for the A/T which I can likely source off of a Z32. They had the same transmission so I can assume the connectors are the same. Right now I'm at a standstill, the coilpack harness was hacked up as well and the connectors from the old harness don't look like the typical 6 pin plugs but rather have a rubber boot on them and a metal clip. In addition there's a single wire plug (round) that comes off of the coil pack harness. Again, not connected to anything. As such I decided to deal with Wiring Specialties for the coil pack harness. Unfortunately they don't make harnesses for A/T which limited me to factory only. That being said, I trust that once I get the coil pack harness and the transmission harness I'll be back in action. From there it'll be time to consider relocating the fuel filter, installing new suspension components and replacing the single pot calipers to something beefier. Yes, I forgot to mention that I've got single pot front and rear calipers. The Gxi came with rear drums so I'm not sure what these are.

After doing some digging (and pulling) I've managed to undo the damage done to the R32 and I discovered I had and R31 ECU powering the car. That's all good and great and wonderful except the engine harness for the R31 is different from the R32, dramatically so lol. I've recently finished swapping out the chassis harness, engine harness and transmission harness over to the R32 one. Thank god that's done lol. Now the challenge becomes what to do with the old harnesses and ECU. Don't suppose anyone needs anything? I've posted on eBay however looking to see if anyone wants to take off my hands. MEC-R43 23710 80S11 That being said, still on the hunt for an R32 ECU, has to be A/T which has proven to be difficult (and expensive) to find as of late.

The badges I have are all discolored actually so there's no telling what it was, I'm assuming red as the car is boosted. Though as you might have seen in my other thread, I plan on doing a neo swap, the challenge is the wiring. I won't go into too many details lol. Trying to score C34 or R34 GTT chassis harness and cluster so that I can run in the car. Wouldn't be fun otherwise.

Thanks @KiwiRS4T we figured out that the RB20 ECU can and will run the RB25 motor, however it won't run the RB25 transmission which is where my headache is. I've been scouring the internet for a while before pulling the trigger on this build. Ideally identifying and sorting out the wiring issues first and moving to mechanical second. There's some pictures of the Skyline. The badge on the back says GTR (previous owner) and the badges on the side say GT lol. So there's no consistency whatsoever, though I'd like to make this car my unicorn and do the unthinkable by dropping the RB25DET motor and trans into the R32 chassis and unleashing a monster onto the world.

@Hcr32typem Thanks I reached out to them and conveniently the guy on the other end said "well we don't really do anything with automatics because they're not reliable. I didn't get his name but it frustrated the hell out of me since I'm in New York and there's no one who wants to touch this car.

What's going on guys, joined a few days ago looking for suggestions and answers to a lot of questions pertaining to my R32 Backstory is I bought an 1990 Skyline GTS-T. All is great and wonderful until I found it was an FR chassis, checked the ECU it was an R31 and the wiring was a rat's nest from hell at the ECU, TCM and under the fuse box in the engine bay. Fast forward to two days ago, I finished ripping out the entire interior, purchased a new chassis harness for a GTS-T and ran everything. Looks good so far. Now I'm waiting on the GTS-T engine harness and transmission harness to finish the project and move onto the interior. Down the road (6 months or so) I'm planning on dropping an RB25DET NEO with A/T trans. The challenge then will be the wiring (RB20 chassis harness + RB25 engine harness + RB25 ECU). Though that's another nightmare waiting to happen, the plan might be (worst case) to just find a wrecked R34 and get the chassis harness from there and hope to god it all works lol.

If you're not planning on swapping the transmission and bolting the Neo motor to the 20 trans, you'll make it work. Wiring for that is fairly straight forward, I believe injector 4 + 6 wires on the ECU need to be swapped and there's some other misc. wiring involved. For Nistune option you can (and should) get the 20 ECU chipped with a Type 2 board and tuned. It's the least expensive option and is very user friendly. Buddy of mine had done the swap and said it's pretty straight forward. Funny you mention this @wicked_two because I'm in the process of doing a NEO swap, though I'm bringing over the R34 trans as well. The idea is to get the engine and tranny in with some modification but the challenge is going to be wiring since I've got an R32 so that means 20DET chassis harness. So far I haven't found anyone across multiple forums who have completed the full motor and A/T swap successfully into an R32 so I'm left scratching my head.

Thanks mate, unfortunately there's no yanks here so I'd be relying on someone over in AUS to yank the Rb25 chassis, engine and trans harnesses. Since that's not a feasible option, any possibility of wiring in the trans to the 20 harness?

Hey guys, I know this is an AUS forum however I'm not having any luck with support in the US for the Skyline, in fact the Nismo guys are less than helpful and rude to boot. Purchased a 1990 Skyline GXi chassis (FR serial number) with an RB20DET swapped into it. It was a real mess wiring wise. I'm still trying undo the damage done. The car is an A/T which is good for me since I'm a cripple. I won't lie, I'd love a 5 speed, but it's hard to shift with my condition. Fast forward to a week ago, I took the car off the road, took the entire interior out (carpet included) and I started figuring out where to begin. I yanked out the entire chassis harness and TCM, it was a nightmare and when I download the pics from my phone I'll share the build. It wasn't pretty. It was rat's nest of wires under the engine fuse box and even bigger mess near the ECU. Somehow an R31 ECU was hard wired into the harness to work. I found a new chassis harness off of a GTS-T which was A/T and came with a new TCM for $200. Sweet deal and when I got it, it was unmolested! How rare is that? I ran the fuse box, I ran the entire chassis harness from the dash back to the tail lamps. Everything looks good. Even came with the Clarion amp and wiring (it'll be removed). Even had the EGT probe for under the passenger side seat, again, something mine didn't have. It took me a 2 days to realize that the engine harness was a separate assembly and I needed to buy that in addition to. So I ordered it and it's on its way now from Japan, $300 later. So now I'm $500 in on wiring but it'll eliminate a lot of issues. I'm assuming the engine harness has the wiring for the alternator and starter unless that's somehow a separate unit? Shouldn't be (hopefully) Halfway into my dimwitted effort to replace the harnesses I decided "Hey let's order an RB25DET NEO with A/T trans." Found one from a reputable source in Canada for $1,700 shipped. So now my big question is what is it going to take to get the 25 motor to work with the 20 harness. I've spent about a week searching and found the general details like swapping two injector wires on the RB20 ECU and RB20 harness when installing the 25 motor. Though the transmission is what eludes me. I haven't found any posts, threads, information pertaining to running an RB25 auto trans on a RB20 harness. From my understanding the RB25 ECU controls both transmission and engine. If that's the case then what's my next step to make it work? Should I just try to find an RB25 auto chassis and engine harness and scrap everything?