Yay...I FINALLY started my Wiring Harness extension!!!

[Troyota]

Just like the title says. I FINALLY started extending my wiring harness. This project has taken quite a bit more time than I intended it to. Finances have been an issue, but I feel like things are finally moving along again!!!

A couple questions that may or may not have been answered already. There are a few groups of wires that appear to combine under some blue electrical tape. Should I extend each of these individual wires, or will it be ok to just extend the single wire coming out of the other side?

I also know the two gray wires (one thicker than the other), the baby blue wire and I think the other is black(?)...the thick wires are the shielded wires that I need to do up the correct way. There is another wire that has me wondering it's Black and Blue and says "ACV-3" on it or something to that effect. Is this a special kind of wire and if so, what?!?

I think that's it for now...I'm just totally happy to get this project rolling again!!! Thanks for any responses in advance.

Troy

 

[Ken]

that black and blue wire is the wire that goes to the starter. just extend as any other.


you can extend the single wire that comes out the other side on the grouped wires you are talking about.


and many others have extended past the shielding, meaning they cut the wire after the shielded part and extend it from there. worked for them. i didn't use this method though.


funny that you mention this; i just removed my extended harness. i'm going to run my new unextended harness through the speedo hole. no solder joints is best.

 

[Troyota]

^Is this actually becoming the "Norm" as far as running the harness through the drivers side instead?!? I've heard at least two people mention this. I'm curious as to how groups like DriftMotion who do a lot of swaps do thiers...if it's still the other way w/ the extension or if they have started to adopt this technique.

 

[rakkasan]

I'm using this method, & DriftMotion does the speedo hole as well, IIRC.....

 

[Troyota]

Once again among the information that would have been useful YESTERDAY!!!!!

I can't believe the technique changed and I didn't pick up on it...and I've already started cutting and splicing my harness.

 

[ropadopa]

Its alright putting the ecu wiring in the right hole and the right place isnt a bad idea....

 

[foreverpsycotic]

IIRC, with going through the speedo hole, you need to repin the dash connectors and extend the body harness. if/when i do this swap, im going with the premade harness from 935 motorsports

 

[Ken]

Well no matter what you have to repin the dash connectors. I'm going to make a jumper harness for the dash connectors when I get my harness in a few days.

 

[935motorsports]

We still do extension, because I don't like to modify any of the chassis during a swap.

I also like the harness to be easily removal during an engine change, if required, like OEM, say 10 years from now.

Doing the driver side does work though, saves time, and cleans up the engine bay. We sell jumper/conversion harnesses for anyone that wants PNP through the driver side. Any year you need.

 

[mattjk]

I like both methods. If you extend it properly, you shouldn't have any problems... it will look usdm stock and you won't have a big hole in your firewall.

 

[Evilempire1.3JZ-GTE]

For most people just simply routing out the speedo hole verry little allows both the speedo and the harness to both go through the original 1jz firewall boot.

The size you route out is the exact same size as the already larger second layer of sheet metal built into the supra at the speedo hole.

The benifits of this by far outway extending the harness.

The ECU still bolts up in the factory location.

The EFI harness is untanted and original doesnt need any mods except one verry minor one to the temperature valve(I removed my power wire and connector that goes to the valve from the 1JZ EFI side and left it in my jumper harness by the body connectors since it is closer to where the jumper harness is then ahead of the ecu off the efi harness heading toward the speedo. Bypassing the heater core you dont need the plug or wire at all or the vavle just no heat in your car).

No risk blowing up your ecu by a dumb mistake or those extended unshielded wires EMI noise out your knock signals and blow your engine up because it cant hear knocking with a specialy tuned shielded microphone because now your also unshielded ignition wires are passing ac voltages into the adjacent knock wires even possibly blowing up sensitive op amps with ac spikes.

Dont have to spend extra $$$ X Time X elbow greese labor getting burnt by solder guns tampering with the factory harness.

adds more mess in the engine bay having more wire loom and crap going just inches away from the top of your turbos across the back of the firewall.


Doing either way going through either the speedo or extending the harness you still need to build a jumper harness that goes between your 1JZ efi system to your Ma70 body connectors.
The body jumper harness is roughly the same length and necessary in any condition you just tap your heater control valve from the 2 wires in the jumper. one goes to the yellow efi power wire the other goes straight to the MA70 body connector.

Another good tip is use the JDM FUSE BOX and the EA2 fuse box connector to avoid extra splices there. Instead of splicing all the wires going into EA2 with the 7M connectors just use the section of the EA2 between the jdm fuse box and the EFI side of the EA2 connector.

 

[suprahero]

After reading all of this, I can safely say, my car will never run again. I have ordered my 1jz, and now see the horror which is the wiring.................:3d_frown:

 

[Troyota]

I was terribly worried myself. But once you actually start on it, it's not as bad as the images you've created in your head are. There are plenty of references and people who have done it enough times that if you have any questions, it can be answered pretty easily.

 

[foreverpsycotic]

in theory if u use the JDM guages, will you need to repin the dash?

 

[Troyota]

Why would you use the JDM guages? Seems like more trouble than it is worth. The guage cluster isn't a direct fit (RHD vs. LHD). The only JDM guages that would fit in the USDM cluster is the Tach and Speedo...the other ones face the wrong directions. The tach is the only guage worth swapping and that's common, and yes, you do have to redo the dash harness.

 

[Ken]

the JZA70 engine harness has a different dash connector to power up the gauges. All you have to do is splice your MA70 dash connector onto your JZA70 harness so it can plug right in.


The wires are even the same colors between the MA70 and JZA70 harnesses for the gauges. For example, yellow/black for the oil pressure gauge is the same between the two.


And for the fusebox, you don't need the JZA70 EA2 connector. The pins from the EA2 connector fit perfectly into the yellow 6-pin MA70 fusebox connector.


What I did, since I didn't have a male EA2 connector, was use 3 MA70 yellow (or grey '89+) connectors. One for fuse, one for the hydro fan temp sensor, and one for the alternator. No soldering involved, just transferring pins from one connector to another.

 

[Evilempire1.3JZ-GTE]

The dash is a P.I.T.A.
I made a hybred gauge cluster

I took the tach electronics including the oil light cut a hole into the 7m tach then used the rubber boot to cover the hole up and put my led through it.
I changed the layout of the idiot lights to match the jdm by cutting the idiot lights out of the jdm gauge and putting them over the blank light sockets then scraped the green paint off the coper tracks so that a light inserted on them would work.

I took the jdm newer style blacked out check engine light and put that on my cluster.

remember i had the pre 89 cluster.
I took only the boost gauge out of the jdm cluster so if i put a lense over it and mount in a pillar on the collum or where ever i could keep the stock gauge.

I have all the jdm & us spec idiot lights in my cluster so if i want to hook up the power light to the nos trigger it will light and have norm on or what ever i did a lot of work and it works well i have low oil warning light & i have low oil pressure switch light and the sender! my oil monitor ecu is behind my gauge cluster.

for the ok monitor ecu i had to splice the alternator wire into it and a power wire from the cluster also behind the dash where the old cruise control used to be nearby i took that wire and spliced it into the wire going into the stop signal of the ecu.

You dont need to do all this i added those wires from the jumper harness going to my gauge cluster custom so i have the best of both worlds.

I also did all this because shortly after getting the jdm clip i was in eye surgery and i spent a couple months recovering and i need a few more touch up surgerys I had a really bad detached retna i have the best medical & retirment plan in the US the medical and retirement plan is so good congress keeps trying to steal money from it. Its a federaly controlled retirement for the railroad it can not be touched by the govt for the past 100 yrs. I just had to wait to get my eyes worked on so i could make my probation so most of the time i worked on one little piece in the gauge cluster at a time.

You dont want to or you cant use the jdm cluster unless your car is rhd because it is facing and layed out diffrent.

 

[Allan_MA70]

ohhhh man all this makes me really want a 1JaayyyZeee!

 

[Troyota]

Woo Hoo!!! I finished the extension today!!! Those shielded wires were a real PITA!!! Especially the ones w/ the two conductors in them!!! Oh well, now it's done. Now I gotta get started on the Jumper Harness for the dash plugs (should be a cinch after the extension!!!)

I still gotta swap the A/C components, the Fuse Box and associated wires (Alternator wires), Install my 5 spd. stuff and finish prepping the engine. Still waiting on Camshaft Seals and Valve Cover gaskets from Champion (on order from Japan).

I've also gotta order a clutch, and hopefully a flywheel. I need to get Gauges (Boost, and EGT). And a catback exhaust. But I feel like a HUGE burden has been lifted off my shoulders with the completion of this engine harness.

 

[Evilempire1.3JZ-GTE]

3 weeks not bad..

looking back and thinking about how you could route the wires through the speedo hole and been driving your car by now..

Sounds like you took your time though and i think you will have a good working harness people who rush the harness extension will have more issues.

I bet you cant wait to drive it now.