The battery is still providing power. After awhile, it too will shut down, as has the engine. I would say you have a worn out Key or lock. Note that car ignition has 4 stages. You can read
Lock will lock the steering wheel. At on the dashboard lights come on. At start, the engine starts and dashboard lights go off. Though not indicated between Lock and On is the radio. Normally the radio should go off immediately you switch off and remove the key. Sometimes if your key or your lock is worn out, the key can come out even when the car is on. So the reason your radio is left on is because you have not switched off completely though your key is off. To make sure the car is completely off, make sure you have locked the steering column. Otherwise you will find the battery is down.
the ACC wire from the stereo is connected to constant power (+12V)
your ground wire for the stereo is connected to the ignition wire of the car
Put it in your car, turn it on and see what happens.
NO
If your car stereo is always hot at all times it shouldn't go out or has connectivity when at "start" Turning the key from "on" to "start" temporarily cuts out the power connectivity. Stereos are not designed to have power at "start" because pretty much the starter uses much amperage and voltage from the battery the seconds while the engine is being cranked
red
Yes it can.
What do you mean charge the amplifier? It's not a battery, so you just turn the stereo on. When the stereo goes on, the remote wire will turn the amplifier on and you're good to go.
Because they're wired that way. Otherwise if you forget to turn the stereo off for instance it might have drained the battery until the next time you wanted to use the car.
Your're hotwire (power cable) may not be hooked right or completely. You may have a bad fuse or a loose one.
http://www.modifiedlife.com/car-radio-wiring-diagram-and-car-stereo-wire-diagram-2001-saturn-sc1/ orange and yellow wires are power
Locate the power drain. You either have a switch on the doors or trunk that isn't cutting off...a light stays on. OR you have a badly installed car stereo/amp/or alarm system. Have you checked your alternator output? You can do so for free at Auto Zone. They can check it "on car". If you can, and it's an aftermarket stereo system, (after checking alternator and battery) disconnect stereo from power and wait overnight to see if better. This could also happen if you have a low-wattage alternator and a HUGE sound system that sucks down power. Auntetr