A third wire, if present, powers a dimmer function for headlights and the dash light.
It’s yellow in most aftermarket head units.
If you find two more wires that show approximately 12V, turn the dimmer switch down and check again.
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Ground wires are also black more often than not but don’t take that for granted.
If you’re free to’t locate the ground wire visually, use an ohmmeter.
The one that shows continuity is the ground.
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Identify Speaker Wires
Figuring out the speaker wires can be a little more complicated.
In most cases, the solid wire is positive, but that isn’t always the case.
To be certain, look at the speaker as you trigger it.
If the cone appears to move inward, you have the polarity reversed.
This is a longer process, but it works just the same.
FAQ
Not necessarily, however,solderingwill give you the best connection for your car stereo.
Just verify you strip the wires adequately and use heat shrinking tubes to insulate the connection.
Wheninstalling a new stereo, take advantage of the car structure.
Hide wires under the carpet or behind the door panels.
Depending on your dash, you might be able to tuck them inside.
