Digi7ech

iTrader: (1)

I'm drifting down in tucson this satuday and my harness decided to have a broken connection somewhere in it. I move the harness and it stumbles and goes to 1 rotor. No good when trying to drift.

So it's time to replace the old conversion harness.

Info
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Car is 88 GTU with TII conversion.
-550cc high impedance primaries
-720cc low impedance secondaries
-Stock turbo
-Rtek 1.7

Harness Requirement: S4 NA efi harness. You can use a TII harness for the conversion but you have to move more pins around to make it work.

First part:
-S4 NA EFI Harness. Low impedance/resistor pack style.


Issues.
-air temp wire patched with crimp connections. Cut line out and solder in new.
-TPS wires were just twisted together. No solder! Repair/patch section
-Missing second X16 interior to efi harness plug. I happened to have one from my scrap harnesses.
-Emissions crap. Remove that useless stuff(helps with conversion pinout issues later as you won't have them!).

Harness stripped down


I believe this is the X16 plug although maybe it's the x15


Now cleaned up for just wipers as I don't have cruise control


Labeling wires and just checking it out


Emissions/Solenoids/Twin scroll/etc useless crap which isn't on my engine.
De-pinning them is very easy. Just get a safety pin and push it in the front and pull the little tab up. Push the wire in a hair and then pull it out from the back and it should slide right out.



Now the fun part.
I'm tired of having cooked harnesses and them rubbing on **** like the TB linkage or getting kinked under the waterpump area and the gernal path Mazda decided to take with it.

I'm going to rewire it and make it hug the firewall.
I need to:
-Extend AFM wires so it can follow passenger strut/fender to afm.
-Relocate Variable resistor/Boosty sensor to cruise control location on strut tower.
-Shorten BAC line
-Shorten O2 sensor
-Lengthen TPS
-Adjust injectors lines depending on location
-Relocate injector resistor pack to cruise control area and only hook up 2 while other 2 get full power(high/low imp).

Here is the harness with it semi cut up and labeled.
You can see cut off..
AFM plug
Boost sensor
Resistor pack
TPS
Semi cut injector lines(power lines cut off at that point)


Now the harness with the injectors cut off but then tapes on at a length which I found to be just right.


Now soldering the injector ground/ecu lines back on at the right lengths. I tend to give myself and extra couple inches just in case I screw up. Note the bottle of Rosin/Flux. It is MANDITORY with these harnesses. The wires ohm out to 1-2ohms BUT have oxidation on them which will prevent solder from making a good connection. The rosin does miracles at getting proper penetration.



I'll post more as I keep working on it. I've got till saturday when I will be driving it 100 miles and then drifting on it.

WingsofWar

Nice Iv got a wire harness that i am rebuilding also. Thanks for the tip on the Rosin Flux i have been trying to find out the name of that product for months, As far as the AFM extension through the fender wall have you measured the appropriate length for it?

BTW have you thought of cleaning up the Driver side engine harness?

Digi7ech

iTrader: (1)

The AFM roughly needs an extra foot maybe a little more to hug the fender/strut tower and have play for engine movement.

I do need to rework the driver harness but I prefer to leave stuff alone until it goes bad. Then fix it.

WingsofWar

A foot? damn i thought it was going to be more.

Either way, i am really looking forward to more of your work. Mainly because it will help me with referencing my own harness build. I am going to end up having the main engine harness wires feed directly behind the intake manifold into the firewall.

Good luck!!

Digi7ech

iTrader: (1)

Updates:

Resistor pack joints


Closeup of boost sensor splices


Boost soldered in


Over all shot of harness. AFM not put on yet. Turns out the AFM needed more like 1 1/2 feet of lengthening


Test fitting to see the exact length of the afm wire before I cut and solder it in place.


You can see the blue wires runnign near the top of the s trut and then going under the hotpipe


BAC shortened. It only needs about a foot off the harness main line


AFM soldered in


Reason why I hate the stock harness path.

WingsofWar

excited to see how it turns out.

BTW regarding (Harness to Wipers/cruise actuator/sub-zero monitor) i see you took out everything so it dedicated to wipers only.

However for that harness on the pinout there is also a line for the preasure sensor(BR/R)/sensor ground (B)/ and Oil Temp Signal(y/w) ...what did you end up doing with those connections?

jdm_emperor

iTrader: (6)

wow, props,
will probably be doing this when ever i find a nice t2 engine

Digi7ech

iTrader: (1)

I have a NA Chassis.
Oil pressure is on the drivers side harness.
Water temp line replaces the boost sensor/gauge and is on the X15/16 plug instead of the one with the wipers.
\
Anyway more updates

TPS wires


Soldered in and at it's end


First layer of tape


Second layer which is self adhering rubber tape


Top layer tape for looks and abrasion resistance. The rubber tape seals against water and stuff but is bad against chafing and cutting.


Spiral loom for more abrasion resistance


I may or may not add some fiberglass header wrap to a section of the harness depending on the heat issue. We'll see.

Last thing to do it slide the firewall grommet onto this and do a once over on all the pins to make sure everything ohm's low. Although i did it as I soldered it but it can't hurt to make sure.

rogrx7

iTrader: (11)

very clean

need RX7

iTrader: (4)

Wow, good stuff. So how did it work out after you finished? I'm taking on a similar project right now. The crap they have wrapped around it from the factory is a huge pain in the *** to get off .

solareon

iTrader: (1)

should have just gone standalone. For the amount of money and time you spent fixing the stock harness you could have made an awesome standalone harness.

either way though good work. I remember seeing this thread awhile back

Digi7ech

iTrader: (1)

I could have found a Haltech or Motec, a wideband, and some one to tune my car for under a hundred dollars?......

/sarcasm
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I did have one initial issue. I made a rookie mistake and followed wire colors instead of doing a line detect and crossed my tps wires. A quick wire swap and it's running like a champ.

Wires look a lot healthier than ones that pass right by the side of the turbo.

I've done a lot of drift events on it since this thread.

Here's the VERY dirty engine bay. I did a 720 spin in some loose dirt at Firebird raceway a few weekends ago.

need RX7

iTrader: (4)

I have a quick question for you. I'm doing something similar to this, and in the process of trying to remove the 4 plugs for the emissions solenoids i found that the wires going to them from the ECU also go through the green TPS check connector. Did you run into the same thing? Did you just eliminate the check connector> thanks.

need RX7

iTrader: (4)

Also, another small snag I ran into, it seems that my alternator plug is part of the same connector that the wipers are on. Was yours this way as well? The wires are Black/white and White/black and they have the same kind of connector as the alternator. The harness is out of a S4 n/a.

Sorry to hound you with questions, I just figured I'd ask you since you did basically the exact thing I'm trying to do.

GREENMAN!

iTrader: (5)

Nice handywork

Digi7ech

iTrader: (1)

I think you're mistaking the common ground or power lines as individual/specific signals.

The wipers and alt wires go to the interior harness. Main relay power/common grounds are fed through the interior plugs.

I still haven't fully mapped those plugs.

I don't remember much about the alt plug. I actually left it out completely on that harness. I'm running an FD alt and have it's power references running off it's own output post.

licensedtothrill

so far this is the best harness tread i have seen. great info