How to Wire a Tractor Volt Meter

Tractors are typically equipped to operate with as few extras as possible. Most tractors lack electric fuel gauges, speedometers, and voltmeters.

For a low-speed machine such as a tractor, it is usually unnecessary to keep track of vehicle velocity; therefore a speedometer is not a critical piece of equipment. Many tractors use a sight-glass or other mechanical method for tracking fuel level, which eliminates the need for an electric fuel gauge.

However, an installed voltmeter can be a useful gauge to have on a tractor. A voltmeter gives a real-time assessment of the battery voltage and shows whether or not the battery is being properly charged.

Red electrical wire

Black electrical wire

4 spade terminals

Soldering iron

Electronic (rosin core) solder

Electrical pliers

Automotive voltmeter gauge

Adjustable wrench or slip-joint pliers

Screwdriver

Drill (optional)

Small metal screws (optional)

Install the automotive voltmeter to the tractor dashboard. If the tractor has an open space on the instrument panel, remove the dashboard retaining screws and install the voltmeter into one of the empty instrument panel spaces. Attach the voltmeter to the dashboard using one or more metal screws.

If there is no free instrument panel space on the dashboard to install the voltmeter, drill two small holes at the top of the tractor dashboard. Attach the voltmeter to the dashboard with one metal screw and tighten the screw so it holds the voltmeter firmly to the dashboard.

Use the electrical pliers to cut a piece of red wire long enough to reach from the battery to the voltmeter. Route this wire from the voltmeter to the battery. Remove 1/2 inch of insulation from each end of this wire and place a spade terminal over each end. Solder one spade terminal to each end of the wire. Cut a piece of black wire long enough to reach from the battery to the voltmeter and route the wire from the battery to the voltmeter. Strip 1/2 inch of insulation from each end of this wire and place a spade terminal over each end. Solder the spade terminals to the wire ends.

Please note: if you're installing the voltmeter on top of the dashboard, you can route the wires through the extra hole drilled at the top of the dashboard.

Loosen one of the top bolts on the negative battery terminal connector. Insert the spade terminal on the battery end of the black wire into the space between the bolt head and the battery terminal. Tighten the top bolt so that it holds the spade terminal against the battery terminal. Loosen one of the top bolts on the positive battery terminal connector. Insert the spade terminal on the battery end of the red wire into the space between the bolt head and the battery terminal. Tighten the top bolt so that it holds the spade terminal against the battery terminal.

Loosen the retaining nut on the voltmeter positive terminal bolt. Place the spade terminal of the voltmeter end of the red wire over the voltmeter positive terminal bolt. Replace the terminal nut and tighten so that it holds the spade terminal snugly to the voltmeter positive terminal. Loosen the retaining nut on the voltmeter negative terminal bolt. Place the spade terminal of the voltmeter end of the black wire over the voltmeter negative terminal bolt. Replace the terminal nut and tighten so that it holds the spade terminal snugly to the voltmeter negative terminal.