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straight forward question..i most likely know the answer but just wanna be double sure...are they the same thing? thanks
The typical terms are:
Yellow - 12V Constant, 12V Battery, Battery Power.
Red - 12V switched, 12V ACC, 12V Ignition.
Techically, they aren't exactly the same thing, b/c if you have a wire from the battery to a toggle switch to the red head unit wire, you have 12V Switched power but NOT 12V Ignition power - but that's not how you would typically wire up a car stereo.
Hope This Helps!!!
Anyone else have suggestions?
2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs
Should be, if I'm reading into it correctly.
Good answer Tiger. Typically(Or in my particular case) when you receive the extra "Red" 12 V wire it serves nearly the same purpose as a (remote turn on) on an amplifer . Its usually something that only requires a low amperes draw, essentially just a constant 12 V. I usually try to hook it to a fuse in the fuse box that only has "power/constant current" when the car ACC is turned on. Which means the HU would only recieve the turn on signal when you turn your key back, or crank the vehicle.
Recently when trying to install the "Switched power" on my car, I tried using a fuse tester but could not find any fuses in the glove box that turn on and off with respect to the ACC control module. Hence, i started looking around for things in my car that turn on and off when I turn the key back. Hence, I ran the "Red" switched turn on to the Positive Wire on my cigarette lighter. CAUTION: If you plan to do this, make sure you install a fuse on the wire, different accessories in your car require different amps to run properly, so be safe and install a fuse to protect your investment. I would figure a 10 or 15 fuse would suffice. Please correct me if I am misinforming anyone @Tiger @ J Ro
lbd - SLIGHTLY off.
IbdTypically(Or in my particular case) when you receive the extra "Red" 12 V wire it serves nearly the same purpose as a (remote turn on) on an amplifer
I was referring to the red 12V wire on the radio, the extra Red 12V wire in some harnesses is usually when the car uses a databus to the radio and signal wires to turn on and off power to the radio.
IbdIts usually something that only requires a low amperes draw, essentially just a constant switched12 V.
Radio wiring has changed over the years. On a modern (90's and up) car and head unit, power is supplied via the yellow or constant power wire and the red wire is essentially a remote turn-on lead to power the unit up and allow the yellow wire to supply power.
On pre-90's cars and head units, the RED (still switched) wire supplied power to the radio and the small yellow wire was only used to preserve clock, preset, and memory settings.
Potentially, this creates an issue when installing a modern radio in an older classic car, as you are better off running the yellow wire directly from the battery rather than using the small memory wire originally provided.
Theoretically, if installing a very old radio in a modern car, you would want use a relay on the red wire for the same reason, but I can't think of a good reason to do this unless you still had a huge cassette or 8-track collection ...
IbdCAUTION: If you plan to do this, make sure you install a fuse on the wire, different accessories in your car require different amps to run properly, so be safe and install a fuse to protect your investment. I would figure a 10 or 15 fuse would suffice.
Good idea to install a fuse on the wire but you use fuses to protect the wiring. Most aftermarket heads only have a 10A or 15A fuse for the entire device, so I would probably use something like a 5A fuse on the small red lead, but the wiring SHOULD support 10A of current.
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