If you're installing accessories like motorcycle dash cam, heated grips, or auxiliary lights on your motorcycle, you’ll often come across the term ACC wire. But what exactly is an ACC wire? What does it do, and how do you find it on your motorcycle?
In this blog, we’ll explain the purpose of the ACC wire, and provide simple tips to locate it. Whether you’re a DIY installer or just curious, this guide will help you understand how ACC wiring works on motorcycles.
What Is the Motorcycle ACC Wire?
The ACC (Accessory) wire is a switched power source that activates only when the ignition is turned on. Unlike a constant 12V wire (which is always live), the ACC wire provides power only when the key is in the "ON" or "ACC" position.
Key Features of the ACC Wire:
Switched Power: Only supplies voltage when the ignition is on.
Prevents Battery Drain: Ensures accessories don’t run when the bike is off.
Common Uses: Powers devices like USB chargers, LED lights, and dash cams.
How to Find ACC Wire in Motorcycle?
Different motorcycles may have slightly different wiring locations. Locating the ACC wire can be a bit tricky, especially if you're not familiar with your motorcycle’s wiring. Here are some effective ways to find it:
1. Use a Multimeter
Set your multimeter to DC voltage. Connect the black meter lead to the battery negative terminal. Probe different wires while turning the ignition key.
The ACC wire will read 0V when off, and ~12V when the ignition is ON.
2. Practical Test Without Any Special Tools
If you don’t have a multimeter or wiring diagram, here’s a simple and practical method you can try when installing a motorcycle dash cam:
Connect the dash cam power cable to the battery:
Red wire → positive terminal (+)
Black wire → negative terminal (–)
Turn the ignition key to the ON position so the motorcycle powers up. Use the yellow (ACC detection) wire from the power module to test the wires on your motorcycle one by one:
Touch the yellow wire to different wires on the bike. And watch the blue indicator light on the power module. If the blue light turns on, you've likely found the ACC wire.
To confirm: Turn off the ignition: the blue light should go off. Turn on the ignition again: the blue light should go on again.
If it behaves like this, you've successfully found the ignition-switched ACC wire!
This method is safe and doesn’t require cutting any wires. It’s ideal for DIY users who don’t have special tools like a voltmeter.
How to Connect Accessories to the ACC Wire？
1. Two-Wire Connection
Red Wire → Connect to ACC power source
Black Wire → Connect to ground (GND)
2. Three-Wire Connection
Option A:
Red Wire → Connect to constant battery power (BAT+)
Yellow Wire → Connect to ACC power source
Black Wire → Connect to ground (GND)
Option B: Alternative ACC Connection
Red + Yellow Wires → Both connect to ACC power source
Black Wire → Connect to ground (GND)
Why the ACC Wire Is Important?
If you’re installing a device like a motorcycle dash cam, navigation screen, or phone charger, connecting it to the ACC wire is crucial—it ensures your accessory only powers on with the ignition and automatically shuts off when the bike is turned off, preventing unnecessary battery drain.
Unlike a constant 12V source, the ACC wire provides a clean and safe installation, eliminating the risk of leaving your device running overnight and draining the battery. Without tapping into the ACC wire, your accessory might stay powered even when the motorcycle is off, leading to potential battery issues or electrical hazards.
Conclusion:
Understanding how to properly connect accessories to your motorcycle’s ACC wire is essential for both functionality and safety. With this knowledge, you can confidently power your motorcycle gadgets while keeping your electrical system safe and reliable.
FAQs About Motorcycle ACC Wires
Q1: What if my bike doesn’t have an ACC wire?
A1: You can tap into another switched circuit (like the taillight) or install a relay-controlled fuse box.
Q2: Is the ACC wire always yellow?
A2: Not always. While yellow is commonly used for accessory wires, wire colors can vary depending on your motorcycle’s brand or model. It’s best to confirm using a multimeter or wiring diagram.
