How to Install an Autometer Tachometer on a Nissan 240SX

Installing an Autometer tachometer in your Nissan 240SX is a great option for a car that did not come with a factory tachometer. Autometer has a complete line of tachometers and many different styles, so choose the one that best fits your needs. Installing a tachometer in your car is a great project for the first-time or novice automotive enthusiast. Select a spot in the car to mount your tachometer before you buy one so you can be sure to get the right size for the space available.

Things You'll Need

• Wire cutters
• Wire strippers
• Crimping pliers
• Crimp-on connectors (a variety is best)
• Wrench set
• Wire taps
• Zip or cable ties

Instructions

1. Select a spot to mount the tachometer. Many people will mount them to the dash or the steering column, but chose a spot that is easy to see from the driver's seat.

2. Calibrate the tachometer according to the Autometer directions by engine size. If your car has a four-cylinder engine, clip both the brown and orange wire loops on the rear of the tachometer with a pair of wire cutters and wrap them with electrical tape. If it has a six-cylinder engine, clip only the brown wire loop. If it is an eight-cylinder engine, leave all the loops intact.

3. Run the green and black wires from the tachometer out into the engine compartment through the firewall. Be sure to pick a path that will not damage the wires.

4. Attach the green wire to the negative side of the ignition coil, or to the tachometer terminal, if your car has an electronic ignition system. The coil is a small, black cylinder with two terminals on the top and a large center wire the runs to the distributor of the car.

5. Install a crimp-on ring connector that will be installed over the stud on the coil after removing the nut and washer from the post. The ring connector is a round connector with a hole in the center. When used on a stud, it will not allow the connector to pull loose, even if the nut or bolt loosens.

6. Strip 5/8-inch of insulation off the wire with a set of wire strippers, slide a crimp connector onto the wire and crimp the end closed with a set of crimping pliers. Install a ring connector on the end of the black wire and run it to the battery. Attach the connector on the negative battery post using a wrench to remove and re-install the bolt.

7. Route the red wire to the fuse box of the car. Locate an open accessory terminal in the fuse box. Install a spade connector on the end of the red wire and plug it into the accessory terminal.

8. Route the white wire from the tachometer to the headlight switch and attach it to the wire that feeds the back lights on your instrument cluster. Attach it with a wire tap. You will need to find this wire using a wiring diagram, or check with the dealer for help. There are too many variations in the wiring on these cars to simply assume it is a particular color.

9. Recheck all of your wires and be sure they are routed away from any sharp edges or hot parts on the car. Adding cable ties, also called zip ties, can hold the wires in place and make this a cleaner, more professional job.

References

• Autometer.com: Installing A Tachometer