tpiroc

Alright folks, there are some good wiring resources floating around here to wire up a 4th gen gauge cluster, but none of them seemed to match an 85 set of plugs properly. The colors of the wires are right, but not the sequence. So, I double checked ALL the wires and sure enough the colors are right, so here's a new guide for an older style connector, namely an 85 TPI dash;


Here's a picture of the plugs;


I also tested all the wires for my ’93 Z28 gauges, and they were entire consistent with the following chart (I forget the original author, but YOU ARE THE MAN);


The best part is, between the ’85 and the ’93, the colors for EVERYTHING were exactly the same! It’s a total cinch.

NOW, this is where it gets interesting. For any of you that have either done this swap, or considered it, you may know that for an older vehicle, the speedometer is cable driven. The new speedo is by the wire, so a VSS (vehicle speed sensor) from a 91/92 car is needed to operate it, also a Dakota Digital box may be required. However, the computer must know how fast the vehicle is traveling, and it is told so by this magnificent optical module! Notice below the little yellow box that has three wires that go to next to the input for the speedo cable;


That is an optical sensor that detects the vehicle’s speed! It has a power in, ground, and a signal output (x2) just like indicated in the later model wiring instructions! Therefore, by leaving the cable connected to this unit, and wiring the optical unit accordingly, it should power the 4th gen speedo just fine! Here’s a pic of the unit removed from the dash;


Now, it may seem hokey to run a cable into the car, just to have the signal converted, but I thought it was pretty sweet, also, by leaving the module hidden behind the dash, there will always be a true to life odometer reading that goes with the vehicle. Anyway, so that’s it, that’s my magical old school to new school solution. Perhaps an electrical thread, but its basis is the interior swap so I plopped it here. All work done in my high tech lab


What do you guys think? Any of this going to be helpful?

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tpiroc

Well, not that anyone appears to care, but just FYI on the little yellow box; the colors are misleading, black is ground, green is hot, and red is the speedometer signal.

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RocVert

Dude I care !!!

This info might be very helpful to me, I am about to swap a 93 bird dash into my 89 Iroc vert (I like a challenge)

So I thank you very much !:hail:

I am still not sure how much of this info will benifit me, but I am gathering all the info I can before I attemp this swap
thanks again

91zconvt

This may sound stupid, but if someone could tell me how to iddentify the connections on the 4th gen plaug, that's be great. You know, where's c1 as opposed to D8?

I've got everything pretty much working except most of the idiot lights, and well, I have like 5 brown wires comming out of the 3rd gen and only like 2 on the 4th gen connector.

GTA4ME

I'm going to make this a sticky....for now.

tpiroc

Right on! Thanks

91zconvt, I'll be working with it most of the day soldering the connections, I'll see what I find. When running through all the wires I got all the idiot lights to light up just fine.

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CamaroRS385hp

so you soldered all the wires? would wire caps (i forget their exact name but you know what i'm talking about) work fine? it's what i use to hook up cd players. also, is there a lot of slack in the wires? i hate wiring things up where you barely have enough space to get your arm between it. for soldering....is it simple to do, and is the soldering tool inexpensive?

tpiroc

Soldering is really the only way to go, it's cheap, and easy once you've got the hang of it. Butt connectors are clunky and very likely to let go eventually. And behind the dash is NOT a place I want to have to root around in. Lastly, I hope you weren't referring to "wire nuts" used in home eletrical outlets and such. Just go to RadioShack and nab a soldering kit for like $7; it comes with a soldering iron, holder, and solder. Just FYI to anyone new to soldering, the simplest advice is to place the tip under the wires, then feed the solder onto the top so it melts into the wires

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CamaroRS385hp

i was actually referring to wire nuts...i've installed probably 10 stereos using wire nuts or electric tape and i've never had a problem with anything coming loose..........but this being a bigger project i guess i'll invest $7 in a soldering kit

91zconvt

I don't know about you guys, and I'm probably going to get yelled at for this, but I have never ever had a problem with good old fashin twisting the wires and electrical tapping them.

I mean, I'm not just talking about taping each one together with one little loose piece of tape, I mean using a whole role just for the gauges. Twist one set of wires together, tape them really good and tight, then do another set, then tape the two sets together, then tape the third set and tape all three together, and so on. Makes for a clean install, when all the wires are taped to each other.

novadk13

an extra 10 mins now save an hour of hassle down the road. My first pickup truck had a radio hacked in like that, after awhile it just stopped working. The reason was because the electrical tape lost the sticky backing causing the wires to expose shorting out to the chassis. I usually use butt connectors or better soldering with some shrink tubing to make it almost 100% sealed. But that just me

91zconvt

If you saw what I was talking about, you'd know there's absolutley no way in hell that these wires are ever comming apart.
The whole bunddle of wires is wrapped for a good foot and a half.

tpiroc

Alright, I managed to solder up the whole cluster tonight and it appears to work good so far! It's a little tough since the car is immobile at the moment. I came across a couple other wires in the 4th gen cluster;

The "Service Engine Soon" light is a brown and white wire that connects to the brown wire #14 in the clear connector (I think).

The "Low Traction" light is a thin blue wire, be careful not to confuse it with the RH Turn Signal wire, also blue.

There are two gray wires, one is the "Security" light, the other illuminates the entire dash.

There is a strange light that's red with an arrow pointing down into a box that's controlled by a yellow and black wire.

There's a large orange wire from the 4th gen cluster that needs to be connected to one of the pink and black wires to power the instruments.

Lastly, there's a red wire that puzzles me; it needs to be connected to a ground though.

Here's a pic of it working (filthy, yeah yeah), but it's ALIVE!!! More progress tomorrow!

Attached Images

wired.jpg (67.9 KB, 203 views)

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PonyKiller87

I have a question about that little yellow optical thing. I am swaping a T56 from a 95 trans am into my 87 Iroc, I am also going to use the gauge cluster. I was hoping this would alow my to connect everything right up with out using that dakota box being that the signal is going from the stock sensor to the stock gauge. My question is, how do I get the computer to know the speed from the gauge?

Thanks,
Kevin

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1987 Camaro Iroc Z Z28
350 Bored over to 355, Ported and Polished heads, Forged Pistons, Balanced/Blueprinted, TPI, Comp Cam 08-302-8 Cam and 2 row timing chain, March Billet Aluminum Underdrive Pulleys, Complete MSD Ignition System(6AL, Distributor, Blaster Coil, 8.5mm Wires), Optima Red Top Battery(rear mounted), Jet Adjustable Fuel Reg, Jet Low temp thermostat & fan switch, Removed Heater and TB bypass, Ceramic Coated Hedman Headers, Removed Cat, Flowmaster Exhaust, T56(from 95 TA), stock borg warner rear with 3.27 posi... The list goes on, and on, and on.....

Things to Come: sub frame connectors, shock tower brace, suspension upgrade(springs, control arms....), ....

Daily Driver: 1996 c/k 1500 z71 short box regular cab Chevy Pickup. Bone stock with a Vortec 305. Finaly put straight pipes and big tips on. Full Phantom Billet Grill.Eventualy it will get a functional cowl induction hood.

tpiroc

If you're using a T56 you will not need a Dakota box, it will be a direct wire up. The T56 has a VSS sensor that you will use. The yellow optical thing is ONLY if you're using a cable driven speedo, and plan to leave it as such. Hopefully I'll have the T56 in and won't even have to tangle with it, it's a "just in case" measure if I don't have the T56 in by the time it's moving again.

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PonyKiller87

So the computer from my 87 TPI setup will "understand" the signal coming from the T56 VSS without any other equipment? If so thats awesome, thats what I was hoping for.

Jstcrzyengh

Ok, so I understand, because I have a 97 console on the way. I need the dakota digital box, which one and how does that hook up. I am going ot have a lot of questions for ya, but i promise to take pictures of every single step for everyone. Gettingg the dash in there doesnt bother me its the wiring that does.

So what box do I need? I will be running a 700R4 and a 92 Speed Density Computer. Does the box work for the HVAC as well as the cluster? Because I want both to work.

thanks man muy appreciado

James

tpiroc

@PonyKiller87; I believe so, I'd like to be more confident with my response, but you never know, there's always other factors involved. It would be more helpful if I absolutely knew the optical sensor's output matched the VSS signal, but at this point it's really speculation. Then again there's a lot of mention of the blasted"Dakota Box", so it may be required.

@Jstcrzyengh; If you're running a '92 ECM you will need the VSS from a 91/92 car. It mounts where the speedometer is inserted and has a wire output that you will use. However, if the optical sensor trick works, you can just use the signal output of that. I really wish the car were running so I could confirm the accuracy of this stinking little box! If the output signal of it is correct, you can just use that. But you may as well convert to a VSS sensor. Like I say, I don't know enough about the Dakota Box requirement to tell you whether or not you need it. It's called a "Speedometer Conversion box".

Hopefully someone with experience can step in and shed some light on the subject of "the box". I'll search around later tonight because I too will need to know this.

Lastly, I finished all the soldering on the instruments and wired the headlight switch and dimmer up; no problems, it all checks out! So far so good!

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3rdGenSS

to answer your questions about that dakota box.. here is how it would be.. if you are useing an LS1 cluster.. (98 and up) and have the third gen tranny then you WILL need that box and your fuel gauge will not work unless you upgrade your gas tank and fuel pump to the ls1 version. if you are useing a 93-97 v-8 cluster then you WILL NOT need the box as long as you have a v-8 in your third gen. you can also use the 98 and newer v-6 gauges but you WILL need the box but your fuel gauge WILL work.. it is confusing i know basically if you have the digital odometer from a v-8 car you will need the box unless you are using the t56 tranny.. then you will not need the box.. any questions let me know and ill try to help... i have been debating doing the conversion to my car but have researched this alot and have alot of info in a notebook lol.... but tpi... if you have any info as to wiring the headlight switch and dimmer so it works correctly and any info on the hvac connections so they work correctly let me know so i can check that with mine before i decide weather to do this ... lol i have had the whole interior from a 98 sitting here for about 2 months now lol

tpiroc

It's your lucky day, camaro86vette, I'm making up an extensive wiring chart that encompases damn near everything (hvac, vacuum stuff, etc.). However it corresponds to a 93-97 instrument cluster I was really trying to get it done before I head to work, but I didn't quite finish it - I need to head to work but will post the info later tonight. Thanks for your input BTW.

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3rdGenSS

most of the stuff should be the same as the 93-97... i know for sure that some are different....but i would like to see what you have... as it looks like the guy isnt going to buy my setup and i am going to put it in mine...

3rdGenSS

tpiroc,
any updates on anything as of yet? keep us informed... gonna get started putting mine in soon and just want to make sure i have everything in line to make it go smoothly

tpiroc

Sorry, I've been out of the house all weekend, but am now on spring break and hope to complete the dash and door panels. I finished putting a new starter on my Caddy today and intend on spending all afternoon working on it

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deadbird

If it helps anyone, here is a 96 HVAC vacuum diagram. At the top I have matched the vac hose colors.

The only functions that I can see that will not work properly is the blend mode and when 'off', the bypass air will come from the defrost vents instead of the floor vents.

The 3rdgen has a one way vacuum actuator for the heat/defrost selector and defaults to the defroster vents when there is no vacuum present. The 4thgen has a two way actuator the defaults to the blend position.

The cure, if it can be done, would be to adapt a 2-way actuator in place of the 3rdgen 1-way. There are a few cars other than the 4thgen that use these as well.

Attached Images

4thgenhvac.gif (46.2 KB, 112 views)

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"I wish my lawn was emo, so it would cut itself."

tpiroc

:hail: deadbird!

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FlamedROC

good..info..to bad im doin a firebird dash...dont think they really wire the same

Jason

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86 IROC-Z---> 74' 4-bolt main 356 c.i. Vortec TPI
243 rwhp/ 343 rwtq
13.00 @102.95 mph
Twin turbo project starting soon

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