OK, I apologize for being a retard/asstard for saying I'm going to do the cluster swap, doing the cluster swap, and not documenting it fully here. So, to remedy that, I will now spew the notes that have led me to a successful cluster swap. Hopefully, they make sense. First off, some pics:
Wiring for gauge cluster with tach:
Wiring for gauge cluster without tach:
Studying the two clusters, you'll notice that the wiring is extremely similar, with the gauge cluster w/tach having 2 extra wires (tach signal from ignition coil or ECCS Control Unit, 2 extra illumination wires, but one less ground). one of the connectors fit on both clusters, but I recommend that you have the tach cluster connectors on hand (unless, of course, you're fearless swapping wires, or a really good electrical tech).
In your car, disconnect the battery (more to protect the ECU than anything else), and take out the gauge cluster. Take some time and study the wire locations. The FSM pages I scanned clearly mark out which wires are which. Now, unless I made a mistake, the wiring is as follows:
no tach loc.........tach loc.........instrument
......5......------....8,21............illumination
......4......------....7,20............illumination
......10....------......19.............hi beam indicator
......17....------......22.............hi beam indicator
......2......------......5..............e brake indicator
......1......------......23............oil dummy indicator
......18....------.......3.............charge indicator
......9......------......13............CEL indicator
.....6,14...------......4..............ground
......11....------.......1..............seat belt indicator
......3......------.......2..............seat belt indicator
......7......------......11..............LH turn
......8......------......12..............RH turn
......12.....------.......6.............fuel gauge
......13.....------......14............H2O temp gauge
......21.....------......24............Vehicle Speed Sensor
......20.....------......18............Vehicle Speed Sensor
..............------......10............tachometer signal
The crap above reads as follows: ex. first line - the wire in pin location #5 located on the connector in EL-57, on the cluster without the tach, is an illumination wire. It must be split and put into pin locations #8 and 20 on the connectors in EL-56, on the cluster with the tach. Its as simple at that.
I don't have the wire colors, but there is a diagram about that in the swap how-to sticky. (if merged, umm, NVM) Now berore you go swapping wires, it is fairly imperative that you have each wire marked/tagged. Now when you are ready to start swapping wires, you'll need a very small flat head screwdriver (one of those mini ones from a basic computer tool kit are perfect) and about 5 feet of, I don't remember, I think 12 or 14 gauge wire, and a solder gun with solder.
Remove the black instrument cover, its held on the dash by 7 screws - 3 on top, and 4 on the bottom. Once the screws are removed, work the cover off about 3 inches, enough to reach behind the cover and disconnect the hazard light button, the rear defogger button, and the "i forgot what it is" stuff/lights on the left. Remove the gauge cluster by removing the 4 screws holding the cluster down. Then pull the cluster about 5 inches back, enough to reach behind the cluster and disconnect the 2 connectors. Pinch the middle of the connector to remove it. Each connector has 2 tabs that can be bent back out of the way. Carefully shove the screwdriver into the back of the connector, using it to wedge the wire loose from the connector. A little study and some manual dextreity and practice, and you should be able to pop out the wire with no problems. Take the wire from the no-tach connector to the new tach connector and line it up to its new pin location. slide the wire in, and it should click into place. If you have to splice wires, say the illumination wire, take about 6 to 8 inches of the extra wire I told you to have. twist it around the wire you want to splice. Then take that wire and put it into one of the new locations. Take the other end of the splice, and put it into the other new location.
EX: remove the wire located at no-tach pin #5. Take the 6 in. of 12 gauge wire and wrap on end around this wire. Install this wire into tach pin #8. Install the other end of the 6 in. wire into tach pin #21. This is done by sticking the wire through the connector and then bending it back over the connector. If you need pics, I'll throw them up later.
The final wire is the tach signal wire. It is found by tracing it from here:
Good luck, its on the left, by the power transistor, hope you can trace it.
LOL, j/k the tach signal can be traced either from the inside of the cabin, or inside the engine bay. The easy way is from inside the cabin. Locate wire #3 on the ECU. It is located on the 12 pin connector. Wire #3 is red with a white strip. Splice into this wire, run it up to the gauge cluster, and install it into pin #10 on the tach connector.
The hard, but clean way is to locate the red wire with a white strip on the 2.2 kohm resistor & condenser relay. Splice into that wire, run it through the firewall, and install into pin #10.
If you want to splice directly into the ignition coil, good luck, you're on your own.
Put everything back together, start up the car, and check all the instruments for correct function. This set of notes is as thorough as I got on this project. Hope this helps anyone thinking of the swap. LONG LIVE THE B12!!!!!!!!!!