tach signal wire is a blue wire with a black cap that ends on the top of the strut tower near the firewall...done
a factory cluster with a tach will work if installed w/o any other work. and aftermarket tach needs the signal wire from the distributor. look for a blue wire comming from the harness to the right of the master cylinder area. also near the hood prop. tap that wire for signal, then run your wires for power, ground, and illumination.
Phillips screwdriver
run it to the blue wire on your distributor. That's the tach lead.
I believe the 93 civic doesn't use a rpm sensor. I have the same car, and if you look closely, the blue wire on the distributer power cable supply's the tachometer with it's reading. For example: i used a after market Tach on my 91 civic and 82 F150. The civic called for the blue and black pair coupler on the distributer. I wired up the signal wire from the Tach to that blue wire and presto, it worked. The F150 was similar. I wired up the Tach signal wire to the trucks coil(in this case the wire was green) and presto, it worked. So try tracing your wires to make sure there aren't any breaks. If everything checks out, you might need to replace the tachometer on your dash panel. i believe the sensor is built it, only the wires run to it. Hope this helps!
The tach signal to the cluster is not on a dedicated wire. It comes over the CCD data bus. Which is a pair of wires that the computers on this vehicle use to transmit messages and information.
green wire on aftermarket tachs are the signal wire i belive
Tach signal wire is located at the PCM near the connector. Use the manual should there be need for help in locating it.
Tach is driven by a motor signal, speedo is from the trans the sensor is bad on the transmission
If you are wanting to install a Tachometer to see your RPM, the following site gives diagrams and schematics for wiring. They list many Honda related fixes etc... Hope this is helpful Either replace the Gauge Cluster with an SI/EX one or install a Aftermarket one. The RPM Signal wire is behind the Gauge Cluster on all models even if not equipped with a Tach
ignition module It's possible that the CDI module went bad. If the car has a tachometer built in to the dash you can use that to make a simple check. Crank the engine while watching the tach. Does the needle on the tach bounce slightly when cranking or does it stay still? If the tach needle doesn't move the CDI module is dead. If the tach needle does move the problem is somewhere else.
pin 48 on the pcm connecter is tach signal connect to your green wire from tach
The instructions will come with the new tach.