How to Connect to an Air Fuel Ratio Gauge

by Cassie Skelley

An air fuel gauge can be connected much easier than you might think. It might seem like quite a task at first, but installing and mounting an air fuel gauge in your vehicle is something you can do yourself in a short amount of time. An air fuel gauge will allow you to monitor the changes in oxygen content in the air your vehicle is breathing so that you can make adjustments to avoid damage to your vehicle or to prevent poor emissions.

Move your shifter into the "Park" position. Open the hood of the vehicle and unplug the negative battery cable using a wrench to loosen the bolt on the negative battery terminal.

Look for a location that you want the air fuel gauge to go to. The air fuel gauge should come with a mounting kit that will allow you to put the gauge on top of the dash. Put the mounting kit on the specific place you want it and drill the screws that came with the mounting kit into the dash. Press the gauge into the mounting kit. If you would like to put the gauge into the dash, cut a hole in the dash the same size as your air fuel gauge using a rotary tool. Place the mounting frame inside the hole and use a flat-head screwdriver to secure the screws to the dash of your vehicle. Insert the wires through the hole in the dash and route them into the engine bay. Press the gauge into the mount.

Route the wires through the firewall hole in the dash. If there is no hole in the firewall, make a small hole in the firewall of the vehicle so that you can route the wires of the gauge into the engine bay.

Strip the end of the power wire from your gauge. Look in your vehicle's manual and find the vehicle's power diagram. You need to find a 12-volt power source that will allow you to have the gauge operating while the vehicle is on. If your gauge does not have a wired power supply wire, cut a piece of 20 - 22 AWG electrical wire the length that you need for it to reach from your air fuel gauge into the engine bay to reach your 12-volt power source. Strip 1/4 inch of the insulation off of the wire so that you can connect it. If the 12-volt power supply is a fuse, insert the exposed end of the wire into the fuse. If it is a coil or terminal, wrap the wire around the terminal.

Look in your vehicle's manual for your O2 sensor, or oxygen sensor. Strip part of the wire coating off of the oxygen sensor. Strip part of the insulation off of the oxygen signal wire from your gauge. Twist the oxygen signal wire from your gauge around the oxygen sensor wire in your vehicle. Wrap a piece of electrical tape around the wiring so that is covered.

Route the negative wire from your gauge to a negative ground in your vehicle. An example of a negative ground is the negative terminal on the vehicle battery or a bolt on the frame of your vehicle. You can wrap the negative wire around a bolt on the frame of your vehicle. Verify that the surface is nonpainted. If you would like to connect the negative wire to the battery, wrap it around the negative battery terminal. Put the negative plug of the battery on the vehicle battery and tighten the bolt using the wrench.

Turn on your car and test out the lights of the gauge. If they are working, proceed with a test drive to see the engine pressure. The gauge will change from lean to rich while driving, and this is normal. If the gauge is not working, retest the connections.

Items you will need

About the Author

Cassie Skelley has been writing articles about computers, electronics, video games and personal care for the Ikana Kai newsletter and Bon Losee Beauty College since 2005. Skelley majored in biology at Brigham Young University-Hawaii and in cosmetology at Bon Losee.