Hopefully someone out there has done this before. I have been tearing into my 79 dash getting ready to install an 84 dash. I am concerned about the gauge cluster wiring. I have gotten down through the plexiglas cover and removed the flat black bezel and have the gauges isloated but haven't removed them as yet. I noticed on the back of the 84 dash (which is out in the garage) that the gauges are all connected with ribbon wiring. Is there one connector that connects to all these gauges because the 79 looks like it is individually wired. Anybody have any lessons learned from this swap? I'm not totally familiar with electrical work but am paitent with tracing wiring. Any roadblocks to rewiring from 79 to 84 dash?

First off: are you merely swapping the gage cluster assy, or are you actually swapping the entire dash board that runs across the car??

From the way you worded your question, it sounds to me like you're only swapping out the gage/idjit light cluster assy; furthermore, I get the impression that your present '79 cluster has the sweep speedo rather than the round one, right? If this is the case, I admit I don't really know whether you can swap the round gage assy directly into a gage pod that held the swept speedo. But if your original cluster has the round speedo/gages, then you're definitely in luck, because it's just about a straight swap. There have been several threads concerning this swap over the past several months. Wiring-wise, the only difference in the connector is there is one additional wire for the tach, and IIRC, there may also be two additional ground wires that have to be added so all your new lights and gages are properly grounded. Of course, you also have to swap out your existing temperature switch (these are mounted in the right head, whether a V6 or V8, located in the top portion of the head above the spark plugs but below the valve covers, and sorta hidden by the sweep-over exhaust manifolds). You need the temperature sensor for gages; the one in there now, for the idjit light, is only a switch and won't provide a temperature signal to the gages. You'll also have to either swap out your existing oil pressure switch or install a Tee junction and a new oil pressure sensor. There is a long writeup on this at this topic: http://elcaminocentral.com/ftopict-14798.html
Note that if you have a V6 with electric choke, your present oil pressure switch provides battery power to the choke. If you merely replace your present switch with a sensor for the gage, the choke will no longer get battery power. What GM did in this case was to install a choke relay on the AC or heater box. This relay is wired to get power from the alternator's big terminal so that the relay turns on when the alternator starts running and providing power to charge the battery. One relay contact is connected to this same power source from the alternator, and the other contact goes to the electric choke. So when the relay is turned on, it provides power to the electric choke. If you have a V6, you'll either want to add this relay (doesn't have to be the original GM, can be something from Radio Shack) OR you can add a Tee to your oil pressure outlet, like I did, and install BOTH your original oil pressure switch AND the new oil gage sensor. In this case, you will have to add another wire (besides the one you'll have to add for the tach) through your firewall to the new cluster, to operate an oil pressure light in your new idjit light cluster. It is easiest to add this wire to the existing pressure switch and to whatever connector pin will operate that oil light, because the new oil gage is already connected to the connector terminal that already goes through the engine compartment to what used to be your oil pressure switch. Simply move that wire from the old switch to the new pressure sensor.

There is another thread here: http://elcaminocentral.com/ftopict-15471.html
..... which goes into cleaning up the gage cluster printed circuit "board". You should do this cleaning BEFORE installing it into your dash just to avoid having to do it anyway, later, when you find your gages erratic.

If you are actually swapping the entire dash board assy, things get more complicated and involved. I'll withhold comment on doing that until you reply.

Not sure what else you need to know...... look the above over and ask whatever other questions come to mind :-D

Thanks for the great info. I knew someone would be able to help. The car is a 79 Caballero with the 305 V8. I want to swap the entire dash from an 84 El Camino into the 79. The dash cluster in the 79 is the round gauges vice the sweep speedo. I was not encouraged by your statement that if the entire dash was being swapped it would be more difficult. But I got a great deal on the entire interior and since mine has been trashed by the sun damage I really need to make this happen. Any additional info you can provide would be helpful.

I didn't mean to discourage you by saying it'd be more difficult; what I was actually alluding to was having to do a lot of wiring harness work.

The reason for this is the '79's firewall connector uses 1/4" spade terminals, whereas sometime in '82-'84 (I don't know exactly when), they changed the terminal to a small crimp-like design. So the internal fusebox/firewall connector won't match up with the '79's connector, unless I'm wrong and they didn't do that connector change until later (entirely possible).

Having the round gages is good but since you're swapping the whole dash anyhow, it really doesn't matter.

I just did basically this whole swap myself; I installed the dash from an '88 Cutlass into my '79 Elky. I early decided I wanted to use the '88 wiring harness with a few personal mods and so that was where I had to spend much of my time over the next few weeks: carefully tracing through BOTH harnesses, noting the differences, documenting where every wire went and was physically located within the two harnesses, then deciding how to perform my rewire.

I went this far was for several reasons:
1. the new dash didn't have the dash-mounted controls of the '79;
2. the '88 wiring harness incorporated wiring for the later pulse wiper/washer system which requires at least one additional wire;
3. the later dash uses a bell-chime for the key-in-ignition and headlights-on alarm whereas the original '79 system only has a really raucaus key-in-ignition buzzer;
4. my original cluster didn't have gages and the Olds cluster uses entirely different wiring that could not easily be swapped from the '79 and modified to work.

The biggest time-consumption item was having to install new 1/4" spade terminals onto the '88 wiring harness, and then also install the additional wires from the '88 harness into the firewall connector (I reused the original '79 fuse block as it wasn't much different from the later '88 version and I wanted to maintain compatibility between the fuse block and the internal firewall connector). The terminals are NOT normally available from your Friendly Local Auto Parts Store (FLAPS); and I only found small blister packs of half a dozen terminals at my local NAPA, and those cost nearly $5 per package. So I went looking for the original source of these terminals. They were originally provided by Delco, of course, which has been called Delphi more recently. Delphi, curiously, has a web site. I stumbled across the part number for one of the spade terminals on one of my schematics and plugging that into the Delphi search engine, lo and behold: I was presented with engineering drawings of the terminals, complete with PNs of all the different versions. There are several types of these terminals, because they accomodate several sizes of wires from the wiring harness, and several gauges of wire. The blister packs I bought from NAPA were flat out useless for anything other than a single wire.

Armed with the original Delphi terminal PNs, I did a Yahooey search on the PNs and came up with a distributor. The distributor, Waytek, does NOT stock ALL the Delphi terminals, only the more-common types. Fortunately, they stocked the ones that I needed the most. And best of all, packs of 1000 terminals cost only a few times what the NAPA blister packs of half a dozen terminals cost :D So I ordered new terminals from Waytek.

But unfortunately, I could only find the FEMALE terminals: Waytek didn't stock the males. So I wound up having to salvage terminals from my original '79 firewall connector.

Not having the proper crimp tool for any of these terminals, I was forced to remove terminals from the old wires, open them with pliers and other sharp objects as best I could (had to obtain numerous licenses from various entities to let me use sharp objects :P and then I soldered the wires into the terminals. This isn't really a good way to do it because the solder wicks back up into the wire, and makes the wire stiff. A stiff wire tends to become brittle over time as it encounters vibration; it will eventually crack and break off. But I sorta figgered that'd likely happen LONG after my '79 was ready for the Yarde :)

Now, you have it much easier in that you're using a Chevy harness. If you discover that your '84 harness does, indeed, have the later terminals compared to your existing '79 harness, then you can very likely swap your original '79 harness directly into the '84 dash. The '84 harness has numerous additional wires for the computer system, none of which you need. It also has slightly different wiring for the delay pulse wiper/washer motor assy, in addition to having the wiper controls relocated to the turn signal stalk (IIRC, this occurred in '84 but I may be wrong and it was later). I STRONGLY recommend that you change over to the later wiper/washer system but if you're more concerned about doing the dash swap quickly with minimum hassle, you don't have to, of course. And if you carefully document what you reinstall into your truck, then when you finally do want to do the upgrade, you'll have some documentation to fall back on to help figger out what you have to change.

I will have to drag out my old, original '79 dash and harness to see what else may be different but I think that's about it. The part of the harness going to the glove box might be different in that I rember that my '79 harness didn't have the power connector that goes to a power lock relay (which is mounted on the right side of the dash close to the glove box). I don't have power locks but was trying to figger out what the extra wires were for :? Also, keep in mind that the '84 harness will have extra wires for the computer; you don't need those and can strip them out if you want.

When it came time for me to reassemble my new harness, I could have rewrapped it with that black non-adhesive tape, which I'd carefully salvaged from my original '79 harness. But instead, I merely used tiewraps. Doesn't matter, either way. BTW, you can buy a new roll of that black, non-adhesive "tape" from NAL for a few bucks.

Gotta get back to work now, ask more questions later today if needed....

OH...... if you decide you want to use the '84 harness and need the terminals for the '79 firewall connector, I've still got a few hundred of them for sale. I also have the original Delphi PNs and the PNs under which Waytek sells them. I'm told there are other distributors beside Waytek.

And NOTE: I wouldn't be the least bit surprised if a reorganization of bankrupt Delphi caused these terminals and all other electrical items of the 1970/80's vintage to become obsolete overnight :cry: :cry: :cry: :cry: :cry:

I'm not discourged just apprehensive since I have not done any wiring projects of this size but then again I have nothing but time. I am replacing the steering column with one from an 84 Monte Carlo so I was planning on moving the washer switch from the 79 dash to the new column and do the dash swap when it warms up some. I only have the dash from the 84, less the harness so I only have the 79 original harness. Would I be safe in proceeding with checking the 79 harness with the 84 dash to see if the wires are compatible or would it be easier to obtain a wiring harness from an 84? There is one on eBay right now with a couple of days left. Also the 79 truck didn't come with power windows or power door locks so I don't have that problem to worry about. I'll just have to get my hands dirty and weigh in there. I'm sure I'll be back at you for more advice soon. Thanks again for the encouragement and info.

Using the '79 harness will fine, although you will have to reroute the wiper/washer control wiring and probably several other things. But at least, it'll save you having to change all those firewall connector terminals :mad: And you aren't planning on adding the things that I wanted to add with my '88 dash, such as the Chime Module (which has a bunch of alarms that sound the chime, such as oil pressure, overtemp, headlights on, etc.). So you're definitely better off adapting your '79 harness. It won't be difficult at all although you'll likely have to unravel at least some of the non-adhesive black "tape" to move wires around.

But I would plan on having the truck outta commission for a week, even if you have all day long to work on it. Mine took me nearly a month of working only at nite after getting home but part of that was waiting for the new terminals from Waytek. And it probably took me 3 or 4 nites just to put the new terminals on.

One other thing I forgot to mention: check out the glove compartment boxes between the two dashes. My '88 dash originally came from an AC-equipped Cutlass and so the box was shaped differently in the rear. It wouldn't fit into my heater-only '79 Elky and I wound up having to reuse the original tan-colored '79 glove box, and paint it dark claret using SEM paint to match the "new" dash. Also, when I mounted the '88 dash, I found the extreme righthand side mounting point of the Cutlass dash was a good inch away from the steel bracket that mounts the right side of the dash. At the time, I ignored this discrepancy and simply pushed the Cutlass dash up and got the bolt installed. But then I discovered the '79 Elky glove box door and box didn't close quite correctly. Now, I believe that if I install an inch-thick spacer between the dash and that righthand bracket, the dash will not be distorted and teh glove box door will close properly; just haven't gotten around to it yet.

In my case, I had to move the four U-shaped nutplates at the defroster vents to match the "new" Cutlass dash's existing screw holes; no problem, since the brackets onto which those nutplates fit has multiple holes for the various models of GM A/G-bodies :P

I also swapped in the steery column from an '86 442 with floor-shift which color matches my "new" dash. Since my Elky has a floor-shift 3-speed stick, the lack of the column shifter on the 442 column was a good match :P

HOWEVER.... in the '79, there is a sorta-U-shaped steel bracket that bolts to the firewall and hangs down on top of the steel strap riveted to the dash, that the steery column is actually bolted to. That U-shaped bracket would not fit properly to the dash's steel column support bracket and I had to leave it off. My column still feels solid but were I to have a crash and my chest went into the steery wheel, the column would undoubtedly rip loose from the dash and go places where it's not supposed to, probably without collapsing like it's supposed to do. I've been planning to drop my dash to redo a cupla other things anyhow, and at that time, will modify the bracket to fit. Just wanted to make you aware that your '84 dash's steery column support bracket may also be shaped differently and you may have to do the same thing. IIRC, that whole bottom area of the '88 dash where the column fits has a different slope to it than the original '79 dash and that required the differently-shaped dash column support bracket; so it wasn't merely a matter of my transferring the original '79 bracket onto the '88 dash.

Also.... does your '79 presently have stereo speakers? If not, and you only have the center speaker (like my '79 did), you'll want to do something about speakers in your new '84 dash, which will have 3-1/2" speakers at each end. Pioneer does have 3-1/2" speakers which will fit even the '83 Malibu with AC ducting; I forget the PN but if you go to their website and search for 3-1/2" speakers, you'll find them. My son had to get a pair for our '83 Malibu wagon. My '88 Cutlass dash still had the originals but I don't even have a radio in my Elky; I never listen to one anyhow, preferring to listen to my "beasts" as I drive :lol:

Thanks for the info. I am in no hurry to do this one. I am studying the wiring while I take the dash apart and just doing my homework right now. I have a few mechanical issues to deal with before I get started. I am replacing the steering column, shocks and heater core. I will probably put the interior in and save the bucks for the paint, since that is the most costly issue. Since this is my "project" car taking my time and learning is more important than getting her on the road. Thanks again, may I take the liberty to look for your help later if I need it?

Sure, just holler :)