S14 Fusebox Relocation and Q&A thread

[Om1kron]

Theory and Discussion post.

Here is the inside of the fusebox on an s14



I have an s13 SR20DET Redtop I am putting in my 1996 Zenki 240sx I obviously will have to change some of the plugs on the lower harness here it looks like.

Here is the KA24DE lower harness.



E205 will be matted to the frame rail.
E204 goes to E18 (which I have no idea wtf that is yet)
E201 goes to E17 - (manual Transmission Models)
E203 goes to E16 - Non applicable since this is not an AT model car.)
E202 goes to E19 - (still looking this up)
E206 goes to the positive battery terminal (which will be inside of the car)



This kinda tells me nothing since I don't know what the fuck "c2, c3, A2, etc" stand for so I don't know what I'm looking for. Mind you I'm using pdf manuals so that kinda hampers my ability to just flip through pages and stumble upon anything.

Now this is the sr20det lower harness.



E206 = 205 from earlier (OBVIOUSLY)

E203 SR20(looks like it could be E201 KA24DE)
E202 SR20(looks like E203 KA24DE)
E201 SR20 (looks like E202 KA24DE)

All previously were running in a usdm s13, and do not look the same as anything on the KA24 lower harness which obvisly may or maynot create some problems for me fusebox wise, not too sure. I think I still have the lower harness to the KA24 at my house so I will have to lay it all out and figure this out later.

Obviously I searched, my gripe is I am relocating the fusebox to the inside of the car. And I'll probably have more info on my gripes when I get into the process of such.

But if anyone knows of any modifications I need to make on the lower harness or how they dealt with the engine bay fuse box plugs when they did a fusebox relocation I would be more than glad to hear your input.

If you tell me to search on fusebox relocation, I hope before you even think of clicking submit that you have read the threads covering this that either have non working photos from photobucket, blurry cell phone cam pics of peoples shitty wiring not explaining how any of the plugs still function, or any breakdown besides "i took the fuse box apart and pulled it through the cabin and hung it with zipties, tada"

that you have read what I just typed, because that information is fucking unicorn is far as I am concerned. So I am trying to make this an easy process for myself, and in the process share some information for those of you looking to do this in the future.

Thank you for your input folks.

[projectRDM]

While everyone has their own way of doing things, here is my method from my own car and two others I did for friends. It's quick and easy if you use your head.

Take the entire harness loose from the fusebox and remove it from the core support completely so that it's laying on the ground. Go inside and disconnect the SMJ and the two power plugs on the backside of the interior fusebox, you now have the entire harness loose. Decide where you want to mount the fuses/relays, I always put them under the driver side of the dash because the main purpose of relocating is to eliminate the extra wiring, putting it under the seat, console, glovebox, trunk, anywhere else just means more wiring and more work.
Separate what wiring will need to go back outside under the hood, headlights, turn signals, fans, etc. Next separate what wiring will be removed completely, if you're ditching A/C or anything like that there's plenty that can go. With it pulled apart, remove that wiring completely from the entire harness.
Now mount the boxes where you've chosen and start shortening the remaining wiring one at a time. If it's under the dash the SMJ is only a few inches away, you can trim a huge amount out of each wire. There are a few wires that are the same color, cutting them all at once leads to trouble. Splice it all back together then run the underhood wiring back outside and reconnect. That part is done.
For the lower harness, you'll need to run all this inside to plug in, going from the alternator, starter, etc. run straight back through the firewall, drill a hole or punch out a grommet somewhere and run it inside to plug back in just as it did outside. The majority of this will need to be extended, but if you're tracking the car you can toss 90% of it, all you really need are the VSS, alternator charging lead and signal, starter signal, and main power from the battery. The OPS and all remaining transmission wiring can be tossed.

Thats how I do it. I never looked at an FSM the first time since it's clear what all is needed just by delooming the harness and what will need to re routed or extended. Take your time and it's cake.

[GSXRJJordan]

I know we've talked about it in your threads, but since you still want a fully functional OEM fuse box, I can only be of limited help - because of the differences in lower harnesses, I decided to hardwire in a few things rather than spend weeks finding proper connectors to do it OEM style. Also, my body harness was in questionable shape, so I integrated my own fuse panel for some things even though my fuse box was wired for them.

Also, I wired my engine harness to standalone fused relays (one for igniter, one for ECU/sensors) off my distribution block so that any fusebox troubles would not effect the car running - this turned out to be my best idea yet lol.

* I cut the fuse box wires about a foot after the fuse box, then sawzal'd the back of the fuse box off so it was more or less rectangular.
* Then I brought all the wires through the firewall grommet into the cabin, and cut about them to length - cut off 6-7ft of wire/sheathing.
* I reconnected most of the wires by color/thickness - there are 4 sets of wires I believe with duplicate colors, and I used trial/error to figure out which ones go where (green/black, red/blue are the only ones I remember) - some don't matter (reverse switch, for example).
*The starter power is hardwired to my distribution block, per OEM, and I brough the connector through the firewall for solenoid/start power - I believe the oil pressure sensor was also on this connector, but I'm not using the OEM sensor so I didn't wire it in
*I swapped alternator plugs so I could use the S14 connectors for alternator power, but I remember having some problem with the "charge" wire (goes to a 7.5a fuse in the box, then to the dash light I believe) - I hardwired it in and never had charging problems again.

As far as advice goes, it's a huge undertaking, and you'll get very familiar with the 18-or-so pages of the El-Power section of the FSM - it all starts with cutting the box to fit where you want it, and bringing all the wires in from the SMJ into the cabin...

EDIT: Just read Russ's post - I forgot about the separating of the headlight/turn signal/etc wires - obv you'll want to loom those up and send them through the firewall. My biggest problems, thinking back on it, came from the S13 lower harness vs. S14 lower harness - I can imagine that without that headache, it would be much simpler.

[Om1kron]

Yeah, the upper harness was the same type of deal... It's working on the harness and working on the engine at the same time that worries me. It's a lot to take on right now so I just want to one shot it.

[Om1kron]

oh yeah throw me a bone here... SMJ is? lol sorry I don't have time to learn acronyms right now. lol

[projectRDM]

SMJ, Super Multiple Junction, the big plugs above the fusebox inside. One is white for the underhood harness, the lower gray does the subharness to the rear of the car.

I'd just stick with using the S14 KA lower harness. I've never understood people trying to use a different harness like for an S13, or an SR car, or a manual harness on an auto car. The VSS on an S14 has it's own connector and all the other wiring needed swaps right over to any other engine, SR, RB, FJ, whatever. The SR starter signal uses a different spade on the end, that's it. Clip it off and put a new end on. After that the alternator is not only in the same place but uses the same plugs so it's a direct swap, the reverse lights (if used) can be kept if it's a manual just as it was or hardwired if it's an auto and it's done. Nothing else needs to be hooked up.

[Om1kron]

sweet deal, i'm going to go out tonight and hook it all up then do my measurements, thanks.

[INeedNewTires]

please take tons of pics, i'm going to be tackling this project soon as well... Also now is a perfect time to relocate the battery if you havent already done so. I'll be awaiting updates.

[Om1kron]

Originally Posted by INeedNewTires

please take tons of pics, i'm going to be tackling this project soon as well... Also now is a perfect time to relocate the battery if you havent already done so. I'll be awaiting updates.

I will actually, I'll need people to double check the work heh!

[onepuff]

E204 goes to the large power wire for the alternator.
E202 has the wires for the charge signal(yellow) and alternator dummy light(white/red) and the wires for the speedo(red,red/yellow)

If you have an idea of what the connector goes to you can go to that section of the manual and find the connector number and see if it matches up. For instance if you wanted to check if the speed sensor is indeed on E202 you can go to the EC(Engine Control) section(pg 103 to make it easy for ya) you will see the E202-E19 connection.

Hope you understand all this. I'm in the process of doing a tuck and engine bay cleanup over the winter. I decided to get a winter beater this year after i went through the McDonalds drivethru facing sideways last year. Ohio sucks. The face on the girl in the drivethru window looking at me thru my windshield was priceless though.

I've got these coming in the mail to replace the engine bay fusebox. I'm gonna try and replicate vaughn4's setup sort of.

Blue SEa 5034 ST Blade Fuse Block w/out Cover - 12 Circuit w/out Negative Bus
Blue Sea 2314 MiniBus 100 Ampere Common BusBar 5 x 8-32 Screw Terminal with Cover

[Flicktitty]

well, i give you guy's huge props,rep,high fives.

i can't even begin to try and re route shit like that, let alone wire anythign up....

can't wait to see how ya did it.

[Om1kron]

Originally Posted by onepuff

E204 goes to the large power wire for the alternator.
E202 has the wires for the charge signal(yellow) and alternator dummy light(white/red) and the wires for the speedo(red,red/yellow)

If you have an idea of what the connector goes to you can go to that section of the manual and find the connector number and see if it matches up. For instance if you wanted to check if the speed sensor is indeed on E202 you can go to the EC(Engine Control) section(pg 103 to make it easy for ya) you will see the E202-E19 connection.

Hope you understand all this.

It takes time to figure out, I think I sat and looked at my harness for two weeks before I actually worked on it. I need to get new copper terminal rings for the wires since the old silver or aluminum or whatever they are are broken or corroded.

I've got these coming in the mail to replace the engine bay fusebox. I'm gonna try and replicate vaughn4's setup sort of.

Blue SEa 5034 ST Blade Fuse Block w/out Cover - 12 Circuit w/out Negative Bus
Blue Sea 2314 MiniBus 100 Ampere Common BusBar 5 x 8-32 Screw Terminal with Cover

One thing I noticed about vaughns fuse set up is that his engine harness came pre built from another company so he had to wire up his lights and crap (body harness) seperately. Not too sure that under the airbox fusebox he has set up handles the same load our fuseboxes do.

One thing I do know is I think I've figured how I will be running things. As far as the fuse box.

Why a 12 circuit? you only have about 5 actualy fuses that size in the fusebox, unless you're redoing and relocating the kick panel fusebox down by the driver door.

Also the second item looks likes that cool ground strip that cursed gtr is using all over his cars chassis.

[onepuff]

I got the 12 circuit because i have 7 so far planned out to be used and i figure it will be a cleaner way to hook up other things like my Profec B, LM-1 wideband, etc. I also have a mac mini carputer setup that i will probably run power for the monitor through this fusebox.

[Om1kron]

ah ah ah, that makes sense, expansion. Eliminating inline fuses. Makes sense and makes for cleaner wiring. I can dig that!

[GSXRJJordan]

Originally Posted by Om1kron

... Not too sure that under the airbox fusebox he has set up handles the same load our fuseboxes do.

The little Bussman fuse box that Vaughn and I run (as well as teh 12 circuit listed above) can handle 30A/circuit, 150A tops. That's plenty.

Originally Posted by Om1kron

Why a 12 circuit?

I've already used 5 circuits (not including my two fused relays for igniter and ECU), and haven't put in the sunroof, blower motor, or defroster. But yes, I also ditched the interior fuse box attached to the SMJ.

[Om1kron]

lol, one thing I could say is your car definitely will be a thief's nightmare Jeff.

[GSXRJJordan]

Originally Posted by Om1kron

lol, one thing I could say is your car definitely will be a thief's nightmare Jeff.

Lol only if something went wrong, and they had to troubleshoot an electrical problem, or if they wanted to hot-wire it and couldn't find any of the billion +12v leads floating around

Wait till you see the "deadbolts" I have going into the doors next month!

[Om1kron]

I know someone on honda-tech did that a while back, there is a fail safe required for those things though just in-case your battery dies... Otherwise you're kind fucked on opening the doors.

[onepuff]

"Deadbolts" hmm. Sounds pretty good to me. Too bad we have those pesky glass windows that seem so easy to break.

[Om1kron]

Originally Posted by onepuff

"Deadbolts" hmm. Sounds pretty good to me. Too bad we have those pesky glass windows that seem so easy to break.

Yes, but the problem is you still wont be able to open or close the doors with deadbolts engaged.

thus some thief would have to climb in your car to try and steal it, cant push start it obviously unless he has some help, and will get trapped in the car pretty much if you got to them before they had a chance to run off with the booty.

[GSXRJJordan]

Originally Posted by Om1kron

Yes, but the problem is you still wont be able to open or close the doors with deadbolts engaged.

thus some thief would have to climb in your car to try and steal it, cant push start it obviously unless he has some help, and will get trapped in the car pretty much if you got to them before they had a chance to run off with the booty.

If you've got the choice to break the glass, or just jimmy the lock, no thief intent on taking the car wants to break the glass - it's loud, and messy... someone who just wants to mess up a cool car would break the glass and then bounce.

Once they jimmy the lock, and find that it's unlocked, and still can't open the door, all while my alarm is blaring - they'll leave the car. That's the idea anyway.

As far as a "failsafe" in case the battery dies, that's a tough one. I think what I'll do is have a 9v battery terminal hidden somewhere (connected to pass side deadbolt probably) and a 9v battery hidden somewhere else, so I can just plug in the 9v to pop the door if the main batt (or my alarm keyfob batt) goes down. Should be secure, and "fail safe".

Back to the wire harness relocating!

[onepuff]

Yea i said it sounds like a good idea especially with all the people out of work right now.

Back on topic. I just got in some more loom and heatshrink so i should be able to get everything loomed up and ready to go back in soon. I'm also planning on making some kind of chart for the pinouts on all the harness connections to kind of consolidate everything in the FSM to make it easier for others.

[Om1kron]

yeah, Jeff's 4th grade drawings of the harness plugs were more helpful than you can even think of.

[GSXRJJordan]

Originally Posted by Om1kron

yeah, Jeff's 4th grade drawings of the harness plugs were more helpful than you can even think of.

Lol see! If you had one of those for the lower harness and body harness, you'd be set!!!

[Om1kron]

Originally Posted by GSXRJJordan

Lol see! If you had one of those for the lower harness and body harness, you'd be set!!!

Well you gave me one for the lower harness, it just doesn't make any sense because there is no routing. just plugs and wire colors lol.

[Om1kron]

s14 lower on the left, sr20 lower on the right notice the difference in size.



unlooming, and surprises.





Sr20 lower again



s14 ka lower unloomed...


My gripe with using this ka lower harness is that I still need it for my Ka that is going in my s13... So bastardizing it so it fits the sr20 is out of the question. I obviously have to fix some connector ends.

So more measuring and figuring out the pin outs (which jeff drew up)

see here.



I guess it's more making a visual sense of it and drawing out the routing. Back to the garage.

[GSXRJJordan]

Originally Posted by Om1kron

My gripe with using this ka lower harness is that I still need it for my Ka that is going in my s13... So bastardizing it so it fits the sr20 is out of the question. I obviously have to fix some connector ends.

I guess it's more making a visual sense of it and drawing out the routing. Back to the garage.

Exactly! I was in the same exact spot with my mess.

The pinout helped me because I really didn't know what I was looking at on the S14/KA lower harness - the S13/SR lower has like half the stuff on it lol. Once you figure out what you need to carry inside the car, though, it all becomes pretty clear. Just have an idea already of where you want the fusebox, and where you're getting power from (relocated batt or not).

[Om1kron]

Alright, so this is what I have gathered so far about the lower harness wiring. After doing a test fit and marking stuff with the sr lower harness.






(SR)E201 needs to be sliced and the plug needs to be swapped with (KA)E202
(SR)E202 needs to be sliced and swapped over to (KA)E203

however there is a catch with the wiring on that I have not written out, things like the vss do not need to be changed over since I am swapping the vss from the KA tranny to the SR tranny and vise versa (since the ka is going in an s13) Same deal with the alternator plug…

I’ll have some pictures once I get into it.

On my SR lower harness after plugging the items up and double checking the wire’s this is what I have come up with.

Example (plug. Pinout example) read from left to right from plug face (where it goes in)


Alternator is E207 – 1. white/red 16ga | 2. white 14ga
Starter is E210 – 1. black/white 12ga
Oil Pressure Switch E209 – 1. yellow/white 18ga
Vehicle Speed Sensor E211 – 1. yellow/green | 2. yellow/black
Neutral Sensor E213 – 1. green/brown | 2. black grnd to starter 18ga
Back up light E212 – 1. green/white | 2. green 18ga

GA = Gauge which = size of the wire I will be adding into the equation.

But more importantly, what the fuck is this? it was tied up with my lower harness but I don't see anything it can plug into on the block or transmission???

[GSXRJJordan]

Looks like your S13 alternator plug. S14 alt plug is triangular, IIRC, and has the starter and oil press with it.

[Om1kron]

thought so. Coolio then, let the hacking begin.