I am trying to install an Autometer Tachometer in a 93 Nissan D21

Question edited for a lot more clarity and correct spelling.

You spelled it 'Techno meter', so that means all your search results with be flawed.

This says you can get a Can Bus interface module.

https://www.google.com/search?q=2005+mitsubishi+lancer+tachometer+pulse+signal

and here is you non Evo ECU Pinout for a 2003, yours will be the same. Pins 58/43 is Tacho

https://www.evolutionm.net/forums/lancer-troubleshooting/572498-ecu-pinout-03-lancer-non-evo.html

Interesting workaround with a Transistor and a couple or resistors

https://www.the12volt.com/installbay/forum_posts.asp?tid=97121

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need some more info is it manual or automatic. diesel or petrol, and engine cc. if auto it can be the signal is not getting to all locations as engine speed goes to auto box first then out of auto box a can go to other devices that need speed signal then to the dash. its the same for manual engines but no signal goes to the auto box control also a bad earth or bad plug on the cam/crank sensor can cause this.

The tachometer gets its signal from the ignition system coil signal so if the car runs then the tachometer is defective and must be replaced or repaired.

Hello
The engine and automatic transmission in this vehicles drive train are fully electronically controlled by a computer called the PCM (Power Train Control Module). Whenever a problem like this occurs the computer stores a record of the problem (there are of course some exceptions to this, like the fuel pump, engine coolant temperature sensor and MAF sensor for instance) in the form of a fault code in its memory, to read these fault codes you must have the systems memory scanned with a special tool. Once the fault code(s) are read you then must perform the appropriate diagnostic testing to find and resolve the problem(s) DO NOT REPLACE ANY PARTS UNTIL A TRAINED TECHNICAIN HAS DIAGNOSED THE PROBLEM TO AVOID SPENDING YOUR HARD EARNED MONEY ON PARTS THAT MAY NOT CORRECT THE PROBLEM

connect tachometer ........Order wire by color
red ignition switch acc
black...ground
green-----Negative coil
white---light

The most common reason for the failure of tachometer on 93 Subaru Legacy is related to the connection of ground wire. Ensure that the ground wire has not become faulty because of wear or corrosion. In case the wire is not functional, it will need to be replaced without which the tachometer circuit will not be complete.

The "Green" wire from the after-market tachometer will connect to the (-) negative side of the ignition coil.

The "Red" wire from the tachometer will connect to an ignition source that has power only when the key is in the "Run" and "Start" position, usually at a "IGN" source on the fuse panel.

The "Yellow" or "White" wire from the tachometer will connect to the instrument panel lighting fuse in the fuse panel usually marked "LPS" or "IP" and there should be a source next to the instrument panel lighting fuse to connect the wire.

The "Black" wire should be connected to a good body ground, and if the tachometer is not properly grounded anyone sitting in the vehicle while the engine is running will receive a mild electric shock from the ignition coil primary voltage whenever anything metal inside of the vehicle is touched.

The "Green" wire from the tachometer should be attached to the negative side of the ignition coil only, and usually (but not always) it is a black wire with a white stripe or it is a solid white wire that will come off from the negative side of the ignition coil and often has a tab on the wire that says "Test" or "Tach" and the wire ends with an open black connector that is used for connecting a diagnostic device or tachometer for diagnostic purposes, and this is the wire that the green wire from the after-market tachometer should attach to. The "Red" wire should be attached to an "ignition" source connection on the fuse panel and have battery power when the key is in the "Run" position only, the "Yellow" or "White" wire should be connected to the "LPS" source on the fuse panel, and the "Black" wire should be connected to a good ground source and if the tachometer is not properly grounded then you will get a primary voltage shock from the ignition coil every time that you touch something metal inside of the vehicle. Let me know if you require any further assistance.

Most likely you will have to use the tach adapter to get a useable tach signal from the computer.

IT'S A BLUE WIRE ON THE BACK OF THE CONNECTOR THAT WOULD NORMALLY GO TO THE FACTORY TACHOMETER IN THE DASH. YOU HAVE TO REMOVE THE DASH GAUGE CLUSTER TO GET AT THE CONNECTOR. THE CONNECTOR WILL NOT BE PLUGGED INTO ANYTHING IF YOU DON'T HAVE A FACTORY TACHOMETER (DX, CX, HX ETC...YOU WILL HAVE TO SPLICE INTO OR CUT THE BLUE WIRE FROM THE PLUG. IT GOES TO TACH SIGNAL WIRE ON YOUR NEW TACH.