OK figured I get some of this down.
As I type the car is back off at the fab shop getting the fuel lines bent and some odds and ends welded on; a few weeks late but hey- its a fabrication shop where time is but an illusion.
You'll remember- when I first bought the car and it immediately crapped out on me, it'd forced me to go though and rewire stuff. That time was an exercise in frustration because I had to first deconstruct what the previous owner was trying to do on everything outside the main harness. Basically i had to go though everything and make sure the chassis stuff that I was building and the engine wiring were working together Aside from a few key changes i left the engine wiring pretty much alone. My reasoning was that I knew the main loom had worked at one point so I was limiting my exposure to causing any new problems by not really changing stuff where I didn't need too. In the course of doing the v1 rewire i had taken note of where I thought things could be improved and put them aside for later.
Fast forward this far into 'fixing stuff' and add some additional things i've acquired that require me to cut into the 'working-but-not-great' loom. With the reasons mounting I was sufficiently convinced that now would be the "best time" and just do everything from scratch.
Deciding on a scratch built harness means that I could tailor it specifically to the car. By removing stuff that I didn't need and adjust the lengths i could have a much cleaner fit and finish, and get rid of the stuff that i wasn't really happy about.
As far as planning this was as big and complex as it can get Theres a lot of things that one needs in order to do something like this correctly. I took measurements and poured over schematics and diagrams so I could figure out lengths of spools, wire gauge size, current capacity, wire color, sensor pins, ECU pins, sensor connectors, wire type, wire wrapping, heat shrink type, fuse type. on and on and on The possibility are truly endless, especially if you care to dig any deeper into what makes one wire or plug better than another wire or plug. The truly maddening part is by altering one component- be it wire size splice placement etc; you have potentially out spec'd something else in the system and suddenly created a compatibility issue that you wont see until you're really far along down the garden path. I don't mind saying right off bat that i ordered quite a few things only to find out that they could not be used, or that there was a better option. Its a bummer, its expensive and it is what it is. I'm sure that doing this type of thing day in and day out... or even having done it just once before could have saved time and effort but these things are all part of learning.
As I was eluding too first thing is first
I needed to lock down positioning of the brain so I could accurately gauge lengths between sensors and the ECU. This would let me extrapolate both the ideal wire gauges and lengths that I would need them in. A good bet is to copy the OEM AWG's- but I had to keep in mind that I was not running any of the main built-in power relays and fused connectors that the car had when it rolled out of the factory, so some some things would need to be changed to accommodate. ALSO on top of these requirements I was planning to run everything through push/pull fuses and an isolated power switch that could kill the power without frying my ECU. This created some pretty convoluted pathways that I'd need to route currents through at the correct amperage. Some real mental gymnastics.
Here's a shot of taking measurements off the main bundle.. I had about 30 note pads
Also measurements of the main fan out to the sensors themselves. I hate rats-nest wiring and wanted everything to be a tight and simple as I could get it.
To make matter even more complicated I also decided to run a CPR Coil-on-plug ignition system. This meant that I would need to wire the CPR controller box to the ECU and have the correct signals go out to the spark plugs. The kit shows up as a premade plug-and-play harness thats meant to run along side to the main vehicle harness. This is good for 99% of the customers but since I had everything apart I figured I would route it all through the main loom to. It would also give me a chance to clean up the lengths and give it some better heat shrink and wire join protection. I found I could also simplify that harness even more since I was already running a non OEM set up.
Cut the ends of the brand new Hondata harness..
wire tape? really guys? Here's a the electromagnetic interference toroid tube that I would reuse in the new loom.
Old engine harness at the top and the COP conversion harness stripped at the bottom.
After figuring out lengths, wire gauge and the best way to route the correct amps, I'd had to tool up so I could actually build it. I can say that this was the most frustrating part of the whole ordeal. I figured that all the information needed on what types of electrical connectors and pins that mate with the sensors would be somewhere on the web...
Not exactly. I knew that they had to be SOMEWHERE- but I got zero help from the dealership and basically nothing form any online forum. The people who did know (companies that make aftermarket harnesses for a fee) pretty much refused to share any information. Since I had decided on doing all this right, reusing connector pins by prying them off the old wires was not an option. Solderless Molex pins weaken considerably after the tabs have been crimped once. Prying them up then back down on a new wire is asking for intermittent electrical problems caused by loose or weak connections.
This is not alchemy and i don't believe in hoarding information- so i've decided to share what I collected during HOURS of calls and research in the hopes that it helps someone that is in a similar position.
Heres the pin connector dimensions on a b18c1 3 wire plug that have the water stopper
And here is the pin dimensions of the two wire plugs
the plugs are made by Sumitomo and are the HW series. These car be pulled outta the junkyard and reused.. or bought new.
Get them here
-http://www.corsa-technic.com/item.php?item_id=226
-http://www.corsa-technic.com/item.php?item_id=255
-http://www.corsa-technic.com/item.php?item_id=521
This is the Molex crimper for a 2.9mm crimp, it has provisions to crimp the water seals too (3.2mm), most don't.
-Molex 63811-1000 Service Grade Hand Crimping Tool-- amazon has best prices.
For the injector clips get these, they're WAY better that the shitty obd1 Honda ones and these come with pins. You will need to heat shrink the back so they are water tight though.
http://www.xenocron.com/obd1-injector-clips-pins-p-166.html
For ECU pins get these-
http://www.hamotorsports.com/obd1-small-pins.html
and these:
http://www.hamotorsports.com/obd1-large-pins.html
For the Hondata CPR harness wire end pins that connect to the CPR box the part number of the connector pins are
1-170291-1
Some of this stuff has minimum orders, you can get lucky and find a place that dosen't if you look. For example, I needed 4 of these...
so yeah.
For the other stuff grab from the junk yard if you can. Its always good to have extras as you can damage clips or ream out holes when taking these things apart. A few extra bucks at the check out can save you the hassle of a whole'nother trip back
Junk yard run...
Here's a good point to say: To do this yourself is NOT cost effective if you have to tool up. Sure there is an argument that you will retain the tools to use again in the future- But honestly, how many people are going to do this more than once? I, personally, like to have tools and experience; even if only to find that i never want to do this again, that is 'worth it' to me. (for example i have a automotive paint sprayer and compressor but will NEVER paint another car as long as i live, but i can)
If you don't care about that- just get a new harness from one of the companies that offer them. It WILL be cheaper and easier in the long run.
If not be prepared to spend
-300 on tools, crimpers, strippers, heaters etc
-100+ on good wires
-250 on good heat shrink and butt connectors
-100 on pin connectors
-100 on misc
-100+ on shipping for above
Time, so much time.
compare this to the cost of a custom built milspec harness delivered to your door. There you go.
Now that I had my parts and measurements and parts i got to work.
This is one half of my 'working box' it keeps everything as organized as possible, which is essential when working with such small parts. A lot of these thing look similar but are incomparable with one another, double and triple check the connector your about to crimp. After about 10 hours I was finding my focus falling apart and I was just about to make some pretty bone headed mistakes.
In the box you can see Deutsche connectors. I'm using a mix of DT and DTM series connectors for power and ground. I'm building them into the system so they it can all be moved around as a unit and able to be quickly disconnected and serviced. More on them as I start to wire the chassis.
For wire i'm using aviation spec tin plated copper multi stranded wire. 16/12/10 awg for respective lengths and amp ratings. This wire is MIL-SPEC aircraft grade and has PVC coating that wont give off toxic fumes if burned.
All the wire splices are heat shrink butt connected, ratchet clamped, then heat shrunk with Raychem es2000 adhesive lined heat shrink. This binds the wires together with a glue that prevents corrosion and greatly increase the pull-apart strength of the splice. This technique will be used throughout the car where wire splices are necessary, but especially inside the harness where service will be impossible. The wrap sleeve you see peeking in is a product called Insultherm. Its a non-fraying resin coated fiberglass sleeve that is watertight and can withstand heats up to 1200 degrees Fahrenheit. Its also made in California, which is cool.
The downside is its a non shrinking sleeve which makes getting the diameter size for the loom your building a little more difficult. I decided to wrap the wire bundles together with 2:1 polyfin shrink to create crisp bundles that then feed those through the insultherm sleeve. The ends of the insultherm are held in place with ES2000 adhesive shrink as above in the splices. Its probably very overkill but i hate dealing with brittle wires and shitty plastic heat shrink that cracks.
Below, you can see the soft silicone plugs that will slip into the back of the sensor plugs to keep the water out. I MAY go a step further and use the resintech R250 goop to seal the back of the plugs, i'll do this only after the harness had been thoroughly tested.
Measuring the strip ends is important. you want the gripper fingers to grab onto the PVC insulation firmly. I ended up stripping the finer wires with a razor blade by hand. Its time consuming but ensures you don't gut strands out of the wire and compromise the connections.
These have been crimped and are water tight when slid into the plug receptacle
Its all about building it in steps and not too rush. Heat shrinking is fun but only to be done at the very LAST step. It helped to think of each ECU plug as a stand-alone where I would only work on that plug until all the lengths to the sensors were complete. Id then Ohm test the connector ends to the plug port to make sure I KNEW where the wire was going- then id go have a test fit on the car. Only after everything was confirmed I would strip and clamp the pin ends on. Only after all that was done would i shrink the sleeves down. Last step was connecting the connector ends.
Here you can see me testing fitting the lengths of the injector leads before crimping the pin ends. Doing these dry installs frequently was time consuming and probably not the best for my lower back but it let me dial thing exactly how I wanted them.
I have mounted the ECU onto a rally car foot pad, Its isolated from vibration by 4 1" threaded fuel safe rubber risers. This insures that if the floor gets wet from a leak or rain the ECU will stay up out of the water and safe. (same is done with all the +12v sources) You can sees Deutsche BUS plugs on the left. these will feed power to the saturated injectors and IACV these are direct 12v that are on a 20 amp beaker the injectors themselves are controlled by a grounding signal from the ECU so the power and amps they require to function are very small in comparison to peak/hold types found on other cars. The black plug side will act as a chassis ground for gauges and the ECM. The majority of grounds for the engine sensors themselves need to be grounded through the provisions in the ECU's circuit board as they have a built-in defeats for grounding feedback. The sensors on the motor CANNOT be grounded to the chassis.
Harness coming along, added injector pins and ready to seal them watertight to the insultherm.
Depinning the connector on the CPR was a HUGE pain in the ass and took about an hour and a half by itself to do.
Figured out a system to depin the plugs while using the probeat the same time.
For the crank cam and TDC sensors I used 4 signal shielded wire with 24 gauge leads doubled up. I grounded the shielding wire and metal wrapper to a 16awg wire and adhesive shrunk it all together. The black wire to the left out the back of the heat wrap will be grounded at the Deutsche grounding bus terminal. This will bleed off any EMF interference that the magnetic sensors see and give the ECU a more accurate reading.
In all this took about 6 pains taking days to complete.
One of the final test fits. You can see how much cleaner and professional the harness is starting too look.
Inside shot during the same verification. You can see all the extra leads that would be used for starter and power hanging to the left. The CPR box is mounted near the ecu by vibration resistant pads where it will be hooked up to the wires hanging off to the right.
Here's the carbon fiber sheet that i cut to use as the harness pass-through on the fire wall. It will be riveted on the fire wall in place- The 1/4" gap all around is intentional to accommodate a silicone doughnut gasket. This will be water tight after final installation.
sideways shot of the routing (upper right is the distributor) the harness is tucked neatly into a slot near the starter.
Now that I wont be using the dizzy anymore I bought a cool billet block off piece from LoCash racing. I also blocked off the vtec oil pressure plug since I removed that from the harness.
In the pic below i'd Starting to wire in the power to the Deutsche connectors from the harness to the chassis side.
I have some cool things planned for this and can't wait to get the gauges and everything else in here. the addition of those will really make it start too feel like the car is actually coming together... As for the wiring harness itsself, its done, as in- all heat shrunk tight. To change anything now would basically be a total do over, and knowing how much work this took it makes me really anxious to fire the car up. I mean, nothing was left untouched so there is A LOT of room for error. Once the fuel system is done I can plug it all in and test. That will be a big moment when it comes.
For now the car is back to the welders for fuel lines and final odds and ends.
In the meanwhile Ive been buying more parts--- and also got this:
All aluminum featherlite 3110 trailer, FINALLY. I unceremoniously sold the ae86 which cleared up the room. Out with the old in with the new. Hopefully i'll have the crx sitting on top of that bad boy on the way to the track within a couple months from now. We shall see.
Until the next time.
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