I have been searching the forums for a thread on this subject but not having much luck. So if I am being repetitive please redirect me to the correct thread. I bought a 90-92 dash and wire harness off of thirdgenranch.com, and want to put it in my 89 I-ROC. Here is what I have so far, the 89 dash mounts are not only 51 inches apart, the 90-92 upper dash mounts are 49, but thet are vertical, the 90-92 are horizontal. Not a big deal couple of brackets and we will be on our way. What is a big deal is the wireing so far I have found the wire bundle that runs the length of the drivers door, to the tail lights, has a 8 wire square plug, where as my 89 has a 8 wire flat plug. As you could imagine this is fustrating. I have wire diagrams for my 89 but not for the 90-92 model. So I dont have any means of splicing the correct wires. If anyone could help me in this department it would be greatly appreciated. Really ANY advice would be great. I cant be the first to have done this. My next question is why the he11 would GM make such drastic changes in one year to the same body style. Sounds kinda Fordish. Sorry I take that back, just really fustrated.

Maybe some high quality photos would encourage some one to come fourth.
http://s980.photobucket.com/albums/ae287/mrbeefy334/

Come on really? 30 hits and no one knows anything? I'm hurting here.

I hate to be the one to say but a simple search will get you the diagrams. After you get those just re-pin or splice the harness in.

Purplehaze have you ever had the carpet up on ur 92 and chased the wire bundle on the driver side threshold? If you have where does it plug into the the tail light harness at? Its a long run of wire so im gussing it connects somewhere in the rear hatch compartment.
BTW I literally JUST found a load of 91 wire diagrams, still flipping through them though. Even if I do make sence of the diagram it wont tell me the whereabouts of this connector im chasing down, so im relying on the forum.

I've made this conversion in the past,.... installed a 91 dash into an 87. The best thing to do as far as installing the dash housing is to find someone willing to cut the brackets from a 90-92 car for Ya'. Then you can drill out the spot welds on your original brackets and weld or screw the 90-92 version in thier place.

As far as the location of the tail light harness connector..... the 90-92 version can be found behind the locking sorage compartment door. ( I JUST looked at my 91 RS to confirm ! ) IIRC the 89 connector is near the rear speaker ??

There was a MAJOR re-design to the Camaro wiring system from 89-90,... mostly due to the "upgraded" dash with air bag !

Before I did my engine swap in my 84, I had installed a 92 RS dash into the car.

It's actually a pretty easy swap overall.

C100 is the firewall connector.

You'll need to locate the diagram from both the 87 and the 92. Then just compare the 2 and see which ones are different. What I did was then just move the pins around to make the 92 from the dash match the 84 on the firewall.

The next harness I believe might need to have some repinned are some on that double connector harness that goes to the computer. I can't remember for certain tho, again look for the diagrams and that should tell you.

The wiring to the tail lights goes down the drivers side, and just below the drivers side tail light there is a harnes that connects the inside/outside wiring.

I have a thread on here somewhere that detailed the progress of my dash swap. Look under my name and you should be able to find it.

I've since done a engine swap on the car, so I pulled the RS dash out and installed a 92 Z28 dash to match the 92 Z28 motor.

Thanks loads cdoyle! You have given me courage knowing it can be done.
Thanks to you too John in RI. I read alot of your threads, you seem very intelligent.
Keep checking back as I'm shure I will have further questions.
Ask twice splice once, I quess.
BTW do either of you rember round about how many connectors need spliceing?
I looked under the dash to try to sort it out looks like there is a lot of different connectors that don't match the car's.

I did this on my 88 IROC. I swapped the dash shells, but kept the 88 harness MUCH easier. All that is required is repining the cluster connections.

I don't remember overall how many, I would say about 10 or so.
You don't actually need to splice anything, just move the pins around on the main harness. They just pull of the harness, and can be moved to another location.

I was able to do them all in about 30 minutes or so. Then you just mount the dash, and then connect the harness to the firewall part of C-100.

Thats actually what started all of this. That little brown wire coming from your light switch that goes across the whole dash down to the console, got a little warm and took out every other wire touching it.
So I found a 90-92 dash thought the only difference was the speedo. Yea I'm an idiot.

Hey cdoyle just found your thread. Really good info there. This subject has got to be getting old to you. I saw where you posted on like 5 different threads on this very subject. Anyway thanks for being so patient.
Oh while im thinking of it, have you ever heard of any one putting the 145 MPH guage inlay over a 110 MPH and recalibrating the speedo for that 90-92 dash?
That would be a way cheaper route, 145MPH speedo are a bit pricey.

I know this isn't helpful for what you are looking for, but IMO the 1990-92 dash is aesthetically far more appealing than the older dashes... The simple/clean layout with the yellow characters is one of my favorites. Anyways, good luck with the swap!

I agree the newer dash is much more refined, with the rounded edges and the more mordern guage setup. I was very pleased when I opened the box and saw it for the first time.

I have good news Cdoyle, that you probably already knew.
The wires in the 89 wire harness are the exact color and letter designation as the 90-92 dash. However I dont think I can simpley remove the pins from the 90-92 harness and put them in the old 89 harness, simply because the pins are smaller in the newer dash.
Do you regalect this with your swap? I can always cut and splice, just wont look as good.

I think I do recall there being 1 or 2 pins that were a different size, but overall most were the same, and could be moved. For the ones that were not the same, I think what I did was looked on my old dash and found a pin the size I needed and cut it off, and then added it to the 90 style dash harness, so it would fit where it needed to go.

but I think I only had to do that on 1 pin maybe 2. The rest should be the same size. Unless they did something way different in 89.

Not sure if you still need them or not, but here is a great place to get wiring diagrams

http://www.austinthirdgen.org/index.php?pid=19

I think that probably has to do alot with the beefing up the thirdgens for those last couple years of the thirdgen shell, they did alot with foam and fillers for seams and integrety, while they were at it I'm sure they figured "Hey lets go ahead and change a few other things, you know just for the hell of it"

So has anyone ever heard of putting 145MPH overlays on a 110MPH speedo and recalibrating? I'm hopeing like hell its possible. Dont really see why it wouldnt be, but then again...
If anybody has any info on this subject let ye come forth.

Well cdoyle, I would like you to know I have the C207 connector figured out. The only pin that changed was for the fans. I guess for when the A/C is turned on. GM moved it from C207 to C100, so all I have to do is move it back. Next I will attempt to tackle C100.

Well, i'm considering the newer dash swap into my 85 as well.

I'm concerned with the tach situation I dont have a tach in this car, as its a V6 what would i have re-calibrate the tach toa V6?

I'm not shure about the V6 at all. I don't think I can be any help here.

You'll have to get a V6 tach to have it be accurate, the V8 will work it just won't read the correct RPMs.

I know, i just didnt know if there was a way to switch them over,

I think i have found a 305 for it anyway,

Cdoyle if you're still listening I have another question.
What exactly did you do for a speedo?
Get the electronic setup and run your own wires to the C100 block?
Sorry to bothering you so long.

Also while I'm thinking of it, the replacement dash came with its own VATS box.
I'm betting it wont work with my factory 89 key will it? What should I do?

ya, I swapped to the electronic setup and then ran my own wires to the C-100.

For the VATS, you can bypass it.
Do a search on here for it, it shows how to do it. It's pretty easy, if I remember correctly it's just running a jumper wire on the relay.

As always thank you.