COMPLETE RB20 into S13 Wiring Guide

Ok... it's not fair for the 25 guys to have a sticky and not the 20's... so... here's the info I've collected (if you submitted the info thanks and feel free to say it's yours if you want to) for the swap:

Feel free to add and/or correct any information...



KA Chassis

Fuel Pump Relay Black / Pink stripe

Transmission Neutral Sensor Green / Orange stripe

ECU Relay Red / Black stripe

AC Relay Green / Yellow stripe

ECU Backup Power Red

Main Ignition Power Black / Red stripe

ECU Power Black / White stripe

AC Relay Blue / Green stripe

Idle Air Control Valve Power Black / Yellow stripe

Brown (to O2 sensor) O2 Sensor Power

now that was the chassis interface...here is the dashYellow / Red stripe Tachometer signal

Yellow / Green stripe Speedometer signal Orange Ignition start Black Ground

Blue / Green stripe AC signal

Blue / Black stripe Water temp signal

RB Engine

White/purple wire Ignition relay

Modified by rbsileighty at 9:00 PM 12/5/2004
Modified by rbsileighty at 9:30 PM 12/5/2004

This was posted a while back, so whoever posted it can lay claim...

S13 KA to RB20 swap

This how-to is for 89-90 240SXs that came equipped with SOHC engines. Wiring up a 91-94 DOHC engine should be very similar, but not quite the same. This how-to also assumes that you already have the engine and tranny installed. If you are performing this swap, make sure you have the engine and tranny installed properly.

1) Run the ECU harness into the passenger side of the car, extending the mass air flow sensor, and O2 sensor wires.

2) Locate 2 plugs on the RB20 motor harness. Both being rectangle and one having 6 wires, and the other having 8 wires.

3) After locating these, find the female end of each of these plugs and cut them back about 6-8 inches.

4) Locate 2 oval plugs on the KA chassis harness, one being grey, and the other being brown.

5) After finding these, cut the Black/red wire, and connect it to the Black/red wire on the RB plug that was just cut.

6) On that same plug, cut the Red wire and splice it to the white/black wire on the same RB plug.

7) Going towards the fuse box, there will be a white wire that goes into the box. Cut and strip both ends of it.

8) Splice the white/purple wire from the RB plug into the white wire.

9) Off of the ECU there is a Black/pink wire for the fuel pump, run a wire from the ECU into the engine bay to the black/pink wire from the fuse box.

10) Now there will be a plug with 2 wires in it on the KA chassis harness, one being white and the other being black/yellow. Find the black/white wire on the other RB plug and connect the two.

11) Coming out of the fuse box there will be a plug that contains a small white/red wire. Take that and connect it to the white red wire coming from the RB motor harness by the alternator.

12) Take the thick white/blue wire and run a wire from there to the positive battery terminal; that will charge the battery from the alternator. The way I did mine was I took the RB battery harness and connected it to the battery as well as the KA battery harness, that way it powers the KA harness and the RB harness, same goes for the negative battery cable.

13) Make sure to use the ground for the starter from the KA lower harness

No one else interested in having this as a sticky? Hey... the RB20DET people need a writeup...

yea put it a sticky! good stuff right there, definetly worth it.

YES Finally. I'm in the process of swaping, I've run acoss most of the before but now i can delete the 50,000 favorites with this info scattered about. what about throwing the gauge wiring in here too, and make it a compete RB20 swap guide. I havn;t seen one of those yet and it would cut down on all the posts that have been covered before.

That was my intent... I'll see what I can do about the gauges...

Here is info for getting the stock tack to work thanks to GTR Shop:

http://www.nicoclub.com/zerothread?id=55405
Modified by rbsileighty at 11:09 AM 12/11/2004

If a mod wants to make their own sticky for the RB20 that's fine, but it's really not fair for the RB20 guys not to have something easy to get to at the top of the forum to guide them with installs.

Yeah I'm with RBsileighty on thisThere should be a RB20 stickyIt'll cut down on a billion post on "how to Rb20"

Shouldn't the r32 rb26 into the s13 be similar to the rb20s wiring? I know the mafs have to be extended and something about one knock sensor added to the lower harness. I am about to do my wiring.

make this a sticky

Kinda small, but this helped me with my swap:

heres another one to help out some (small, but save and zoom in):

Using RB26 injectors in an RB20 with a dropping resistor

corrected tac fix link:

zerothread?id=55405

How about the S14 RB20 swap? Same thing?

Bump.

Meanwhile, let's list all the companies that carry RB swap or RB replacement parts!

McKinney Motorsports carries RB25 mounts and driveshaft and their mounts lower the engine and set it back.

What's that company that carries RB20 custom mounts?

Phase2 stocks RB series parts.

I was sure this was stickied once. Why is it not stickied anymore?

Does anyone know where I can find the differences b/t this wiring walkthrough and one for a 91-94 S13? I can find a nice pdf about RB20 into a s14 and this into a SOHC S13, but nothing on an RB20 into a 91-94 DOHC S13. If anyone wants to make a detailed write up for a RB20DET into a '92 S13 FB , for instance, I wouldnt object!

rbsileighty wrote:That was my intent... I'll see what I can do about the gauges...

Here is info for getting the stock tack to work thanks to GTR Shop:

http://www.nicoclub.com/zerothread?id=55405

Modified by rbsileighty at 11:09 AM 12/11/2004

I cant find the page above. Please tell me more about getting the stock tack to work with the RB motor! Thank you

Here's the updated link:zerothread?id=55405

Let me know if it works... I haven't had time to try it yet.

It works fine as I did it on my first try. Great info and thank you.

BTW, if you have done the swap b4, would you like to pass on some of your valuable exp. to me as I am doing it this week? My number is 8582546577 or leave your number here so i can call u! My name is Kenneth

The best way to contact me is at [email protected]

Well i have a quick question. I have a 90 S13... am i going to have to buy new power steering lines just as if i was putting in a KA24DE or a SR?

Also my biggest issue right now is the intercooler issue. I heard putting in the side mounts are hard but then again someone told me they aren't. I was planning on sticking with the side mounts for a while but i might just go front mount and just save up a bit more. I guess my real question is.. how difficult is it to install a side mount? And is there anything special that has to be done for a front mount? i was thinking of getting this...

http://www.ssautochrome.com/level.itml/icOid/1438

scroll down and you will see the RB20DET/RB25DET FMIC kit.. would that be a smart buy? I know i am asking quite the n00b question but this is very important to me to get it done right

Yes you have to swap the line like you would in an 89-90 SR swap.

looks like a decent kit... ask what brand it is first. I have a hybrid which looks just like that one. My old motor that went in a buddy's car reacted very well to the kit, but he did custom piping. I could tell you about mine, but the blown turbo limits any feeling on how good it is...

As far as SMIC vs. FMIC... do it once, do it right. The only thing I didn't do this with on with mine was the turbo... and it's blown... case in point.

how did you break your turbo.. i thought i recall you saying you did it with a hammer? lol is that right?

by the way thanks for the info man

Yep... in order to clock the turbo to fit the RB I had to hit it with a hammer! Actually that's what the guys at the diesel service place did for me since they couldn't figure out any other way... same conclusion I had made before I brought it to them. Oh well...

No problem... glad I could help

For the RB20 you have to HAMMER in the turbo to make it fit... man that scares me and im about to do the swap! ahhh! Was that just for your car or everyones?

I just dropped mine in yesterday, no hammer here.....

Carls wiring is much more updated. I will copy and paste it in here for you guys. I am sure he would if he wasn't on a road trip. This is pretty accurate and I only had a few questions but it is more up to date than that other wiring procedure. Here she is.

So you wanna… Wire a HC32 RB20DET for a S13 240SX

Well this is a simple little guide that I (Carl H) have decided to put together after completing my rb20 swap into my 240sx. The wiring pertains to a DOHC car but it seems in practice that SOHC and DOHC swaps are the same or near the same. Most of this information was derived from Brandon Baune’s (nismo241 on most boards) rough wring guide, some things I added or subtracted to fit my needs. As with anything of this sort no warranty is provided and if you **** up your own car then its your problem not mine. Make sure you know what you are doing and if you don’t, then make it a point to find some one who knows what they are doing. Also don’t copy this document without giving props to me, plagiarism is bad, and I wont be happy if someone comes out and starts to claim that this write up was their idea. Anyways enough of that lets get down to the real meat of the topic.

Ok. So you want to wire the car up eh? I hope that you have all the wiring harnesses from the clip, if you got a motor set then you might be in for a few trips to radio shack. First off you will need a few things before you wire the car.

1. Soldering iron and soldera. Do it right, don’t half *** the wiring by twisting it together, chances are it will fail and you will pay for it later2. Electrical tape3. Plumbing emergency tapea. You can get this at the hardware store in the plumbing isle, this stuff is great for wrapping up your finished harnesses and is similar to the stock wire wrap, wont make the wires sticky like electrical tape will.4. Wire tap-insa. Get these from radio shack, they sell blue ones and red ones, if you want to do the wiring without soldering you will need a package of blue ones, but either way you will need a package of red ones.5. Razor bladea. Good for cutting through the wrap; don’t cut too deep then you will have to repair wires.6. Toolsa. Pliersb. Wire strippers

So you have all the tools and supplies needed eh? That’s good, but you will still need a few things from the skyline. See the harness in the engine bay that goes all around it? Get it out of the clip; you will need to cut some plugs off of it.

Locate the 6 and 8 wire connectors on the engine bay harness; they are big, gray, and quite square. Clip these back from the harness as far back as you can preferably about 20 inches, you will have to unsheathe/unwrap the harness to do so.

On the ka EFI harness locate the oval gray and brown plug, these were located near the fuse box in the 240, clip these back from the harness about 6in. or so. On my swap I only needed to use the gray oval plug but on the SOHC swap you might need to use both. It just depends, I know that the fuel pump wire is on the brown plug on my car but why use a plug when only one wire is being used?

Well by this point you should have located the major plugs of interest and should have them in your hand, so on to the next step.

Lets start the actual wiring by denoting which wire goes to which wire on what harness. I’m going to list the wire colours in columns with the RB wires being on the right and the ka wires being on the left.

KA RB Black/Red  Black/Red (Thick wire)Red  White/Black (Thick wire)Black/Pink  Black/Pink (Thin wire)Black/Yellow  Black/White (Thick wire)White/Red  White/Red (Thin wire)FB White  White/Purple (Thick wire)Alt. White/Blue  Terminal (V.Thick wire)

Ok, so we have the basic wire colours and what they connect to but where are the wires you say? Well have no fear as I have the locations of the wires and where they go along with pics for clarity.

The KA black/red wire connects to the RB black/red wire coming off the 6-wire RB connector this wire is on the gray oval ka plug.

The KA red wire connects to the RB white/black wire also coming off of the 6-wire RB plug, this wire is also on the 6-wire RB plug.

The KA black/yellow wire is actually on a plug on the side of the fuse box, you can clip the plug off of your old ka and connect it to this for a clean connection or clip it off like I did, please note that the white wire is just cut, it is NOT spliced into the black/yellow wire and the black/white wire. The black/white wire is on the 8-wire RB plug.

Here is the write up for the lower harness

I thought it would be a good idea that while I had my motor on the ground I would do a write up of what needs to be done to the KA lower harness to make it fit onto the RB.

Series II RB25DET S13, all S13s should be the same. Do this at your own risk!!! I will not be responsible for your mistakes and this is based on my knowledge and experience with my RB.

WARNING: do this at your own risk!! I am not responsible for *Jack* blah blah, you know how it goes. Now this guide is only for those that know basic engine wiring, have some clue so far on what is going one but just need to know the specifics to get it started. Thanks OpenSource...

Also included I will should you how to properly splice wires. Don't use gay splice/butt connectors they will only cause you pain in the long run and I will flame you. Spend the time and a little bit for materials and I promise all will go well and you will be glad you listened to me! Now on with the show...

Prepping that Lower KA harness for your RB

1) Take off both harnesses from the KA and your RB motor 2) 3) From your RB Harness cut off the Oil Pressure sending unit plug, it has two wires - YLW/WHT and B and it is located right next to the oil filter. 4) Now you are going to want to cut at least this much off because it has to be slightly extended.



The Yellow with white wire is for the oil light and the blue wire is for the oil gauge. The stock KA cluster doesn't have an oil gauge so the blue wire won't be used. If you are using the RB gauge cluster than you want to be using this blue wire and are going to have to hard wire it to the cluster. If you are using the stock cluster than cut the blue wire, or leave a pig tail on it if you plan to use a oil pressure gauge because that’s what its going to be hooked up to.

And lastly the write up for RB-s13 cluster.

KA to RB cluster wiring guide.Suits r32 type-m gts-t only.

Wiring colours for the ka cluster and rb cluster are from ‘93 cars may not be the same for earlier years.

RB

Plug 1Gnd – black with yellow stripe (ground)Tm – blue with black stripe (temperature gauge)Oil – yellow with white stripe (oil light)Belt – yellow with black stripe (seat belt light/chime?)Door – red with white stripe (door open light)Exh – orange with black stripe (exhaust gas sensor light)Ign – green (ignition switch power)Acc – blue (clock power)Bat – yellow (no idea)

Plug 2Ill+ - red with blue stripe (illumination power)Ill – black (illumination ground)Om – yellow with blue stripe (oil pressure gauge)Tam – yellow with red stripe (tach signal)Beam – black (high beam ground)Beam+ - red with green stripe (high beam light power)Gnd – black (ground)Sw1 – yellow with green stripe (no idea)Sw2 – black with yellow stripe (no idea possible ground)Hicas – green with white stripe (hicas warning light)Brk – white with purple stripe (handbrake/brake fluid warning light)Chg – white with red stripe (alternator charging light)

Plug 3Ign – green stripe (ignition switch power)Bm+ - white with blue stripe(boost gauge signal)Bm – black with yellow stripe (boost gauge ground)Fm – green with blue stripe (gas gauge)Gnd – black with yellow stripe (ground)Fuel – red with black stripe (fuel warning light)T/l – white with green stripe (left turn light)T/r – green with yellow stripe (turn right light)

KA

Plug 1Chk engine – red (check engine light)Cruise – black (cruise control ground)Cruise+ - green with white stripe (cruise control light power)Abs – blue with red stripe (abs light)Exh – red with blue stripe (no idea, different on every car)Fm – green with blue stripe (fuel gauge)Fuel – red with black stripe (fuel light)Ill – red with yellow stripe (no idea)2p – yellow with green stripe (no idea)Japanese symbols – yellow with blue stripe (no idea)

Plug 2Ill+ - blue (clock illumination)Ill+ - red with blue stripe (illumination full)Tam – yellow with red stripe (tach signal)Japanese symbols – yellow with black stripe (no idea)Beam 1 – pink with black stripe (high beam ground)Beam 2 – red with green stripe (high beam light)T/r – green with yellow stripe (right turn light)T/l – green with black stripe (left turn light)Gnd – black (ground)

Plug 3Door – red with white stripe (door open lamp)Ign – green (ignition switch power)Oil – yellow with white stripe (oil pressure light)Brake – yellow with purple stripe (handbrake/ low brake fluid light)Tm – blue with black stripe (temperature gauge)Chg – white with red stripe (battery light)Gnd – black (ground)

The following refers to the plugs that the cluster plugs into on the chassis harnessTie cluster to body ground, which is the black wire on the black plug.White plug red/black is fuel pump lightBlack plug red/black is batt (clock power)

To get the boost gauge to work you will need the boost pressure sensor from the clip (near the brake master cylinder) and the associated wiring.If you remove the chassis harness and unwrap the boost sensor plug all the way back to the SMJ (huge wire connector deal) you will have more than enough wire to run to the cluster.The wires for the boost pressure are as follows White/blue goes to the gauge cluster for the boost gaugeBlack/yellow is ground, so tie it into a ground.Green is the power wire so tap it into the ignition switch wire on the cluster (also green).

Wiring the oil pressure gauge.On the lower rb harness there are 2 wires one being yellow/white, the other being yellow/blue.Locate these; lengthen them so that you can bring them into the cabin near the cluster.Connect the yellow/white to the yellow/white on the cluster.Connect the yellow/blue to the yellow/blue on the cluster.

Contact me (carl h) at [email protected] of psykodragoon on aim.Don’t copy my work as yours, that doesn’t sit well with me.Any errors feel free to point them out.

I am sure this will be helpful to you guys.

~ANDREW~