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Discussion Starter · #1 ·
[Opening Statement
The car: 1988 CRX SI
The Engine: B18C1
-Things Specific to this project:
-Only running one 4wire o2.
-No Knock Sensor
-No IAB's (I have S2 IM)
-No Fan Switch plug included as I dont have one at the moment.

Now since I have a slightly custom setup for my wiring, there are going to be some things different between what I'm doing, and what you might want to do.
It's not that hard, so if there are additional wires you have, that I dont, that need included: just figure whether they need extended, then tuck them appropriately.
If I'm wiring things you don't have (Vtec stuff) just ignore it.

And as a general starting point for this, my instructions are going as if you have your front bumper, fenders, Glove Box, the Driverside Footrest, and the Center console removed. I would advise taking your seats out aswell, it will make things much easier.
A tip also, never do this w/o the engine in the car. You need to test fit everything to make sure everything has proper length.
Another tip, if possible, do this w/o the radiator installed, the hoses REALLY get in the way....
ONE more tip...Don't completely wrap things until your 100% CERTAIN of them (I.E. your tuck is done except the final wrap) keep it wrapped once every 4 inches or so to keep wires together, but dont fully wrap in case you need to make alterations.
Now, just ONE more thing, I swear, this is important here: In my pics you see how I pulled the wiring not through the little circular hole, but bent that out a bit and pulled them down to the side. I highly recomend doing this instead of putting them through the hole. I put it through on the DS, and to the side on the PS, and I have all sorts of fitment issues on my DS, trying to get my cornerlight in without it bein poked out by the big jumbles of wire. I could shorten my wires a bit to make room, but then it'd be hard getting the lightbulb into the light, know what I mean?
And one more note, on my 88 on the Driverside, there's only a 6 pin (6P) connector. On the 89-91 it's a big ol 14P connector. Dont ask me what wires are what on the 89-91's: IDK.

Ok, so first things first, easiest place to start:

If your running AC, skip this and you'll just extend and tuck these wires as neccessary.
If not, get rid of this wiring if you havent already. It's really simple to tell the AC wiring from Headlight and other wiring b/c it's all in one strand, and all enters the cockpit at one point, in the upper left of the firewall.
Here's the CRX Manual's Diagram of the AC Wiring:

Now here's one of the actual wiring, all removed:

Like I said, it all goes into one spot. Unless you specifically want to maintain the wires, cut them at the firewall, and unplug them under the dash (pictured below) and pull the remaining wire through the dash and its outta there!

Congrats, your free of AC wiring in the engine bay!

So this sides got all the major ****. Fuse Box, big 14 Pin connector, etc. all the good stuff that makes your engine bay so cluttered you go to these lengths to free up some space!
-Start off by unplugging all your headlights if you havent, aswell as the Windshield Wiper Motor, Fuse Box connections, etc.
Here's a pic of the Fuse Box wiring undone:

And a pic of the wires from the Headlight Loom that cross into the fuse box/14 pin connector wiring. These will eventually have to be extended, or however you do it as a couple of them are just grounds:

-Now it's really simple: Just unplug everything on this side, and shove all the wiring and connectors into the cockpit.
When you do so, leave ALL the engine connections connected. The only one's you'll have to disconnect to move this wiring are: The Map Sensor and the plug next to it, the starter wire (black with white stripe) all the rest will/should reach.
-When you shove it all in, it comes in in 2 bundles:

Bunch 1.The wiring that WENT into the engine bay.
This wiring USED to go INTO the bay. Now it doesn't :thumbup:

Bunch 2.The wiring that GOES TO THE ENGINE, and connnects the above mentioned wiring (Bunch 1)

Here are pictures of what it looks like with Bunch 1 pulled into the Cockpit:

Now on Bunch 1, all the connectors/things brought into the Cockpit can stay there EXCEPT: The Map Sensor and the plug next to it. I dont know what the plug next to it does, but I dont need it as I dont use the Stock Map Sensor location, as my S2 Intake Manifold has one on it. So in my case, I only need to run the Map Sensor BACK into the Engine Bay, you may need to do the other plug aswell. To run the Map Sensor back in there, just split the loom and fish the 3 wires for it out of the sea of other wires, and run it back into the bay.

Now there's a Dust Boot that was on Bunch 1 that went into the Engine bay, that kept **** out of the cock pit. It was important to me to maintain this, so I could put it on Bunch 2, the bunch that is now going into the Engine bay, so to continue keeping **** out of the cockpit. So I just depinned the wires where needed and strategically fit it over the plugs and got it off. While doing this, I seperated each strand of wires from the giant Bunch. That way, when I go to shorten them up, it'll be easy to do it without getting confused. Here's a pic of them all seperated and bundled:

Once you've done this, all there is to do is run the Headlight wiring through the fender wall. That is pretty much self explanatory, you'll have to extend a few wires and depin some plugs but you'll get it. I haven't done it yet so I don't have pics, but I will tommorow. For now if you need to see what I'm talkin about, the places to route the wires through are pictured in the other Wire Tuck how to's.

Now for the fun part. This is probably the most complicated and tedious part of the tuck. So lets start out easy:
For reference purposes, this is a drawing of what your Engine wiring harness looks like FROM THE FACTORY:

Fuel Injector Wiring - The FI Wiring is seperate from the rest of the engine's wiring (which it is taped into). Now I'm OBD1, so now FI Resistor Box. But I didn't just solder the wires together, I repined the OBD1 Injector wires into their proper spots on the 6pin connector they should go into, that connects on the Driverside.
Either way, OBD0 or 1, your injector wiring is seperate, and I recomend seperating it.
Here's a pic of it seperated and loomed up. Notice the 6 pin connector on the end?

IMPORTANT: There is a BLUE wire in the 6 pin connector. This wire IS part of the engine wiring harness. De pin it, and it will eventually be ran through the engine harness and out by the Alternator, to meet the 6pin connector and plug in :thumbup: this will be detailed momentarily.

Now it's time for the majority of the wiring. This is again pretty self explanatory:
Based on where the wires are headed, un-loom them, bunch them together properly, and tape them as you go. Remember when doing this the idea is to have as little wire as possible showing, so try to keep things in the FEWEST number of looms as possible, aswell as angling the wire in the way you'd want it permanently hidden.
The only wire that'll need extended is the Starter Wire (Black with White Stripe) Pictured below (connecting to the starter on the right)

I kept it simple: 1 loom for the engine connections on the rear and IM, one loom for the TPS and MS, and one for the Coolant Temp, TW Sensor and Vtec plugs. I had a RyWire subharness but I just integrated it into the wiring: vtec plugs in one loom, and ran the o2 wiring in the Rear loom.

Here's a pic of the looms taped together that would eventually be the rear loom, in my test fit of how I'd run them as one. As you can see, I just got them situated properly and used little bands on tape to mark where they'd end up eventually.

Here's a pic of them wired together the way they'd end up:

And one of them finalized and loomed up:

I didn't take pics of the looming process of the other 2 looms of the Engine Wiring b/c their so simple and self explanatory, I mean their all RIGHT THERE, you just loom them and bundle the wires, simple as that.

So now you should have your wiring for the engine minimalized and tucked to a decent degree. If it's not perfect no biggie, you can always alter it in the future. When doing something like this for the first time, trial and error is key.

Here's a pic of how I wired everything engine related together, and a few shots of the FI Wiring and Engine Bay (please keep in mind this is mid tuck):

Passengerside Wiring through Fenders:
So you've got your wiring in the cockpit and your ready to run the wiring throught the Fenders. Excellent, Great, Grand, Wonderful!
So here's what we're running through there, by number and pictured below (NOTE* - The Windshield wiper needs ran through here too, but is not pictured do to my fucking up!)
1. Radiator Fan Relay
2. Horn Buttons
3. Grounds
4. Bumper Lense
5. Headlight wiring (cut for wiring to JDM headlights on my Car)
6. Corner Lights (or Corner and Side marker is JDM fenders installed)
7. Radiator Fan
8.Windshield Wiper Motor (not pictured)
* on the note of the WW Motor, it is NOT on the headlight harness (the one we're tucking right now) Its on the wiring from the shock tower near the fuse box.

Also plese note I'm not a wiring Guru, so this isn't done to the fullest like Ryan or EF8Kid would do, but it's good enough for me. And by this I mean the mounting of the Relay and Ground Box, I'm sure they relocated them somewhere else to make it a little cleaner.....but if you cant see it, ya cant see it, know what I mean?

So basically what we're doin here's simple:
-The ONLY thing that's gonna reach w/o being extended are the corner lights
-So we're extending every other wire.
-When extending each thing, I would recommend you cut off the plug, and plug it in, and then figure out how much wire you need to extend them properly.
-The WW Motor wiring goes right up into the fender (in the same spot as the rest of the wires) and right out to the plug, right there.
-I didn't feel like extending all the grounds for the Grounds Box and wires for the Fan Relay, so I just extended the few necessary and I'm mounting them under the fender, in the area pictured.
-Other than that, everything is going to the same place, it all goes in 1 loom up til when it comes out of the fender, then you'll have to seperate each thing's wiring.
-Once all the wire lengths have been figured out and cut, solder them onto the WIRING HARNESS first, and then loom them up long enough to go through and out the fender.
-Run them through the fender, and when the come out, solder each wire to it's plug and then loom em up and your good to go.

You can run them out the little hole you see in the pictures where the corner light goes, but I didnt, I pryed that a slight bit to fit the plugs through, then bent it back. I did this so my Wiring is easily removable (all plugs fit through the hole but the Fan plug, so I only have to cut it off if I wanna bring the wiring out, instead of all of them)

So that's about it for how to tuck the passengerside. go do that ****!

Where they come out:

Please note I have one of the corner light's wiring retained in the fender area to go to my JDM Sidemarker light, and that the WW Motor wiring is not pictured at all. Just want to make sure everythings clear.

Driver Side{/b]
I dont have pics at the moment, but it's very simple and self explanatory after you've done the PS and Engine. Basically your gonna just extend the wiring of your Fuel Injectors and few other wires, to reach into your cabin.
*****This will be VERY different on 89-91's, as they have 2 1/2 as many wires going in on the DS for the Engine*****
Other then that, it's simple, you just wire up all the DS Components:
-Corner light
-Bumper Light
-2 WW Resevoir Motors
That's it.
All of their grounds need extended.
I'll get DS pics here soon.

This is the Passengerside after I relocated the Ground Box and Radiator Fan Relay to inside the cabin and wired the WW Motor, the second loom of wires you see are the WW..

Here are pics of how I've arranged the wiring inside the cabin.
I've mounted the Ground box by the kick panel, and the relay is next to it.
The ECU is located behind the center console, so I can easily remove it nightly.
Now as I said before, I haven't shortened any of the wiring so it's not neat at all, but it fits. I don't have the time to shorten it all right now, or time to deal with possible problems that could arise if I do so, so it's not shortened.
But eveything fits nicely, if I could find my ECU cover it'd cover it all.
Tell me what you guys think:

Couple of pics of the Bay done:


· Registered
9,754 Posts
Good lookin man! A little different (and better) than I did it. Could you resize the pics please? If you want to send me everything I can make it a pdf for you like I did with mine, so it's universal and all the pics are saved with it.

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117 Posts
Discussion Starter · #6 ·
downest said:
Good lookin man! A little different (and better) than I did it. Could you resize the pics please? If you want to send me everything I can make it a pdf for you like I did with mine, so it's universal and all the pics are saved with it.
Thanks for the compliment man, I really appreciate it

Yea, I meant to ask if the pics should be resized, I left some of them large since this is stuff people want in extreme detail, but I can resize no prob, it shouldn't effect anyones comprehension of the write up.

What do I send for you to make the PDF? that sounds cool

· Registered
9,754 Posts
I did it on my D16, it's pretty similar. The biggest/hardest/longest part is the headlights and non-engine stuff, which is the same regardless of the motor. For the harness I just ripped it all apart and measured where it all needed to go to get back through the firewall where I wanted it, and pulled out wire where I needed to. I also pulled out the resistor box and rewired the FI for that in the process of the tuck, basically made a whole new engine side harness. The engine part only took a few hours.

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117 Posts
Discussion Starter · #10 ·
Masta said:
Thanks for taking the time to do that, must have taken you forever.
No prob man.

As far as time goes, Downest is right, the longest part is doing the lights and whatnot.
The engine's really very simple and requires almost no extending, basically you just undo the loom, move the wires where you want'em, retape, and reloom.
As far as the rest goes, it's basic, you'll very easily be able to tell what needs extended and what doesnt, so you just do what needs done, and try to be clean about it.

My whole tuck took about 12 hrs over a long course of time, but I'd guess I could probably tuck a bay start to finish in about 6 hours.

Next time around I'll clock myself, but I'm gonna go a little slow to make sure I get my write up perfect, and note all the 88/89-91 wiring differences I find.

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117 Posts
Discussion Starter · #13 ·
^ Aw yeah man I never got around to remounting mine like that, good thing your on this board to toss up your pic!

thrasherx said:
does doing a wire tuck make it harder to diagnose electrical problems later on or otherwise maintain/repair?
Not if you do it right.
If you make all your solders in convenient places, where it's easy to get a voltmeter to, to test for power and whatnot.
This was something I was worried about before starting, but as nothing engine related needed extended, I wasn't worried.
I've never had a problem with anything since my tuck. There was an issue at one point but it ended up bein a broken wire, no biggie.
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