90 wiring harness swap

[cheap90gsx]

So I've run into a problem converting my wiring harness to a 94 harness. The one plug that doesn't match up I believe is the chassis harness. I'm curious if anyone else has swapped there harness? And if I would be able to switch the plugs off the old harness to the new one?
Just to clarify, the plug for the chassis harness is slightly different from 90 to 94 where it plugs into the engine wiring harness. Can anyone point me in the right direction? I couldn't find any helpful information. Thanks.

 

[cheap90gsx]

I know I'm not the first one to swap to a newer harness? There has to be some info out there some where?

 

[1gdsmftw]

if you are talking about the one on the passenger side of the car just splice the old pigtail in according to colors thats what i did now my harness is universal!

i am swapping right now and im stuck at the pigtails behind the ecu 91 has a 10 pin connector and 90 is a 7 pin

 

[donnie2783]

I have a 90 and swaped everything out of my 91. I had gotten smart about that problem. I cut the melted 90 engine harness plug off and then cut the burned 91 plug off of the harness in the car off and then spliced them together and made an adapter harness. I done the same thing with the plug by the ECU but the only problem with that is that there will be 3 wires left over and I am trying to find out where they go. I hope this might help someone with a tip about making an adapter . If someone knows where the 3 left over wires go would also be a great help. thanks.

 

[1gdsmftw]

yours is only 3? i have 4 left over! can u key me in on which ones you got matched?

 

[donnie2783]

The center plug by the radio area. I only have 3 wires left over a "green/white stripe,green/brown rings,and black/brown rings. I have all the others color matched up. On the chassis harness by the glove box are all color matched up. I wonder if I would need to switch any around for my tach to work haha.

 

[1gdsmftw]

are you running a 91 ecu with it as well? if not i dont see why you would

 

[donnie2783]

I am currently running the 91 motor,trans,xcase,rearend,driveshaft,front axles/hubs,engine harness,ecu(and its a 5speed so no TCU). so everything else is out of the 90 model.

 

[1gdsmftw]

yeah right now i have a 90 motor and a 91 trans and xcase myself

i swapped the packs and the igniter...i got the harness on the passenger side perfectly done while i was down there i pulled the ac core out of its box

but the center plug im stuck on myself! does your car start how u have it?

 

[donnie2783]

Yea. It starts and runs great but i'm tracking down an idle gremlin thats hiding. I just currently don't have a tach. I dont know if the 90 guage clusters tach even works haha. I just wish I knew what those 3 wires controled or atleast where they went. I cant find any info of them.

 

[1gdsmftw]

hmmm i guess this might be why we need a 91 cluster

then ill match those colors and see what happens

 

[donnie2783]

In a few days i'm going to find me a 91-94 eclipse or talon at a salvage yard and just take the whole wiring out of the car.I am going to fix that wiring problem haha.I can get a wiring harness for 75 dollars and I know my local salvage yard has 3 of them. I am going to just weight reduction my car ,and then change the whole harness I guess is what I am going to have to do .I pratically rebuilt this car from ground up as it is. It was nothing but a shell .

 

[1gdsmftw]

im about to pick up an internal harness for 25 bucks shipped XD but im using it for pigtails and references

 

[donnie2783]

Sweet. Not bad. I wish i could find one that cheap .So as soon as you can find out where those stray wires please be sure to let me know .Looking at the backs of my 90 and 91 guage cluster i see that theres a very slight difference on the back circuit board and the oil psi guage is slightly different. the 91 has an "anti lock" light and the 90 don't?

 

[1gdsmftw]

abs was an automatic all wheel drive feature sacrificing lsd in the rear end not a year to year thing...

and when i figure this wiring out ill hit u up first hand! than following up with a full accurate write up on how to do this damn swap since nobody wrote the right damn thing

I went outside and roughed the snow! Attempted to match some wires! turnes out now I am down to 2 wires left over instead of 2!

What I noticed is this.

Do you have a relay that plugs into a 4 prong connector as well as the big connector next to it? They should be in 1 harness

The 4 prong connector has 1 wire in it that has the black with brown rings

the big connector I plugged the yellow the blue the 3 reds and 1 other damn my memory! but I will be reviewing this before i finish and posting a full walk through on this on my new forum i created!

 

[donnie2783]

Well tomorrow I am going to be installing my 91 harness. I guess i'm going to be selling alot of 1g parts off of a 1990 as soon as i find them all.I don't have a clue where to trace the wires to but good luck because I couldn't find any diagrams and my chiltons don't help .

 

[1gdsmftw]

a friend of mine just sent me a pdf file of the entire wiring diagram

im ###### just gonna do a continuity test

 

[donnie2783]

I couldn't find any information I needed to help me out. If I would have known I was going to have to go through this much trouble I would have swapped my 91 engine harness for a 90 engine harness honestly.

 

[1gdsmftw]

yeah i gave up ....i found a 1gb gst im buying to replace this thing xD

 

[donnie2783]

I just spent all morning putting this harness into my car. The only plug thats a little different is on the driver side. Just tried to start it and guess what.......... NOTHING. I am just getting fed up with it. I think im just going to part it out I hate to say. But I cant keep trying to fix this thing I need this thing running so I can go back and forth to school and not have to rely on borrowing rides from people. Either that or I am just going to find one that needs a motor and just put my motor in it.

 

[1gdsmftw]

yeah pull the motor and trans dude and find a good rolling shell...harness bs is stupid...

 

[donnie2783]

Ok well it is done. the harness is in ,and it does run. But I still have one problem I had before I started and that is one of my injectors not firing. I will figure it out. Oh and I dont have a fuel guage now. somehow the wires are different.