The wire that shows less than 12V at that point is the dimmer/illumination wire. Its typically orange or orange with a white stripe. The wire that still shows 12V is the accessory wire, which is usually red in aftermarket wiring harnesses. If only one wire ever had power in this step, it is the accessory wire.

What is the accessory wire in a car stereo?

Basically it tells the amp the stereo is on and it should turn on too. The accessory wire is what triggers the stereo to turn on when your ignition key is in the accessory position.

What color is the power wire on a car radio?

Depending on the type of car you have, each wires function can vary. However, typically the red wire indicates Power, black indicates Ground, yellow indicates Remote, and striped, multicolored wires indicate speaker wires.

Where is the constant 12V on a car?

To find a constant 12v source, you will use the positive probe (typically red) of your multi-meter. Start by grounding the multi-meter to a vehicle ground point (metal). Once the multi-meter is grounded, ensure that the ignition switch is in the off position.

What is 12V accessory power?

The 12V socket, also known variously as a car cigarette lighter or 12V auxiliary power outlet, is the primary method by which power is delivered to portable electronics in cars, trucks, recreational vehicles, boats, and in a handful of other contexts.

What is 12V in a car?

The 12V socket, also known variously as a car cigarette lighter or 12V auxiliary power outlet, is the primary method by which power is delivered to portable electronics in cars, trucks, recreational vehicles, boats, and in a handful of other contexts.