How to Wire a Sunpro Tach

by Michael E Carpenter

Sunpro is a maker of gauges and tachometers, and has been producing these devices since 1935. The tachometer grew in popularity in the 1960s and 1970s with the rise of sport and muscle cars. Tachometers are devices that measure the revolutions per minute (rpm) of the engine. This helps the driver monitor the vehicle and shift gears at the optimum times. Sunpro tachometers are simple to install and should take about an hour to complete.

Step 1

Connect the black wire to a clean unpainted ground using a ring terminal or other safe grounding means.

Step 2

Connect the red wire to any battery harness that provides power when the power is in the "On" position. The red wire will provide the power to the tachometer. Do not connect the red wire harnesses that provide power in the "Not Off" or "Accessories" such as radios and lights.

Step 3

Connect the white wire to the instrument panel lighting circuit connected to the dimmer control switch. Connect the white wire to the dimmer switch control wire by using a wire splice. Insert the dimmer switch wire into one side of the splice and the white wire coming from the tachometer into the other side.

Step 4

Connect the green wire to the negative side of the ignition coil. The ignition coil terminal may be listed as "TACH", "TACH TEST", "DEC" or "ECU" terminal. Use this connection on vehicles with a distributor.

Step 5

Connect the green wire to the tachometer output lead on vehicles that have distributor-less ignition systems. Consult your owner's manual to find the position of the tachometer lead on your vehicle.

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