How to Find ACC (Accessory) Wire in Car

Home » How To » How to Find ACC (Accessory) Wire in Car

How can I identify the ACC wire in my car?

The ACC wire is usually red and slightly smaller than the primary power line, which makes it easy to find in a car.

Your car’s ACC wire lets you use electrical accessories while the engine is turned off. If you get 0v when the vehicle is turned off, it’s most likely because the ACC isn’t set to a constant 12v. When the ignition is set on ACC or the vehicle is operating, the red wire labeled “ACC” should have power.

Crutchfield banner_car_stereo

However, you can only ensure this if you know how to find ACC wire in a car first. In this post, you will learn the step-by-step process for finding the ACC wire in your car so it can turn on your stereo.

How to identify ACC wire with a multimeter

Step 1: Find a Constant 12V Source

Set your multimeter to the appropriate scale, attach the ground lead to a proven good ground, then touch every wire in the speaker wire with the other lead. Make sure the ignition switch is turned off.

The constant 12V wire, often called the memory wire, can be found when the multimeter shows around 12V. In the majority of aftermarket head units, it is yellow.

Step 2: Check for the Dimmer and ACC Wires

Power on the ignition switch, crank on the headlamps, and switch up the dimmer switch, if installed, all the way after you’ve marked the 12V wire. Set the dimmer control down to recheck if two more wires are displaying about 12V.

The dimmer wire is the one that exhibits less than 12V at that juncture. Orange (with or without a white line) is the most common color for this wire.

The wire that is still showing 12v, which is generally red in color, will be the accessory wire.

When you check the wiring using the multimeter using this guide, the ACC wire will be the only one with the power.

Hey, there mobile audio lovers! My name is Vincent Talbot, founder and chief editor at Ask any mobile audio fanatic, installer, or company rep what makes a good car speaker, sub, or amp, or, better yet, why he or she prefers a certain brand over another, and be prepared to endure a litany of opinions, viewpoints, and passion-fueled perspectives. To be honest, mobile audio shopping can be a daunting task without a guide, so I’ve assembled what I feel are the best products to consider to make things easier for you. More.

Why you should trust me?

Mobile audio is my passion, so before I put anything in front of you I exhaustively research a broad range of products, review all the available information on them and ultimately make a curated list of recommendations. As a result, I want this site to be a trusted resource that you can rely on and that is not rigged by brand sponsorship, so you can use this information when you are planning your new mobile audio upgrade.