- 1). Remove the tachometer from the box. Set the tach to the number of cylinders that your vehicle's engine has. This procedure will vary according to the brand of tachometer you are using, so consult the instructions that came with it for detailed instructions.
- 2). Determine where you are going to mount the tach. The tachometer will come with a mounting bracket that goes around the tach and allows it to be bolted to the location of your choosing, such as the dashboard. You may also be able to mount it where the stock tach is mounted, but this will be more involved, since you will have to remove and disconnect the stock tach. Make sure you mount it close enough to the gauge cluster that you have enough wiring to reach the tach. Also keep in mind that if you drill holes and then later remove the tach, the holes will be visible. Common mounting areas are the dash above the gauge cluster or to the left of the cluster.
- 3). Mount the tach by drilling holes and using the supplied screws or bolts to fasten the mounting bracket to the mounting surface.
- 4). Route the red wire that comes out of the back of the tachometer to the fuse box. If there is no red wire, consult the directions for the proper wire that should run to the fuse box. Find a terminal on the fuse block that is an open power source that switches on when the ignition is switched on. Your fuse block will likely have several terminals where you can connect the wire. A shop manual for your vehicle will tell you which terminals are available for an accessory like a tachometer.
- 5). Use wire strippers to remove about ½-inch of the insulation from the red wire and then crimp the wire to a spade electrical connector. Wrap electrical wire around the connection to fasten the wire and the connector together. Install the end of the wire onto the fuse block.
- 6). Connect the white wire from tachometer to the wiring harness that goes to the instrument lights. Splice the white wire into the instrument light wire with a crimp-on wire connector. Clamp the two sides of the wire connector on the white wire and the instrument light wire. Clamp the metal wire tap down onto the wires to connect them. For an even more secure connection, wrap electrical tape around the connection.
- 7). Fasten the green wire that comes out of the back of the tach to the negative terminal of the coil, which will be bolted to the engine. Use a ring connector fastened to the end of the wire and bolt the wire to the coil by removing the nut with a wrench on the negative side of the coil, sliding the ring connector on and then reinstalling the nut.
- 8). Fasten the black wire to a suitable metal ground in the interior or run the wire into the engine bay. Use a ring connector attached to the wire and bolt or screw it to a suitable ground location. Make sure the wire is fastened to a bare metal surface to provide a strong ground. Start the vehicle and check to see that the tach is working correctly.
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