How Do You Hook Up a Sunpro Tach?

Adding an aftermarket tach could be a great idea.

Tachometers, used to count the amount of revolutions an engine is making per minute, are advantageous gauges to install in your vehicle to prevent you from over revving and damaging your engine. Sunpro, a manufacturer of automotive aftermarket gauges, makes a variety of tachometers, all of which must be wired in the same fashion. You can decide where you want to mount it, but you must wire it correctly if you want it to function properly.

Things You'll Need

• Sunpro tachometer
• Wire cutters
• Electrical tape
• 12 volt test lamp

Instructions

1. Strip 1 inch of shielding from the ends of each of the four wires protruding from the back of the tachometer. There will be a black, red, green and white wire.

2. Mount the tachometer in an easy to view location that will not interfere with your ability to see the road clearly. Make sure you have also selected a route in which to hide the wiring to facilitate a clean installation.

3. Connect the black negative ground wire to any bare metal surface in the car. If you are unsure of the suitability of the chosen location, connect the alligator clamp end of your test lamp to the positive terminal on the battery, and touch the test lead tip to the metal surface, if the lamp glows the location is good, if not, select another.

4. Connect the red wire to the output side of the instrument lighting fuse. This should be labeled in your fuse panel, but if not, cycle the instrument lights on and off while testing the output side of the fuses with the tip of your test lamp while the alligator end of the lamp is connected to the negative terminal on your battery. The test lamp will turn on and off with the instrument lights when you have found the correct connection.

5. Connect the white wire to the dimmer control switch, if you wish, to the dimmer control output side of the fuse. Check for this fuse in the same fashion as in Step 4.

6. Connect the green signal wire to the ignition coil. Feed the wire through an opening in your firewall and into the engine bay. In a carbureted model vehicle, connect the exposed end of the green wire to the negative terminal on your ignition coil. In a fuel injected vehicle, connect the exposed end of the green wire to the tachometer terminal on the electronic ignition control box; see your owners manual for this exact location.

7. Set the selector switch labeled 'CYL' on the rear of the tachometers casing, to the number of engine cylinders the engine in your vehicle has. Turn on the car and test for proper functionality, including the lights and dimmer.

Tips & Warnings

• Hide all wiring by wrapping it with electrical tape and placing it along the seams of interior body panels.

• Ensure all exposed electrical wire connections are covered in electrical tape to prevent shorts from occurring.

References

• Sunpro; Tachometer Installation Instructions