Can't save radio stations, have
A common error wiring an after-market car stereo is where to connect the BATTERY and ACCESSORY wires. Under most conditions, these two wires do NOT get connected to the same point. The BATTERY wire connects to, well, the 12 volt positive terminal of the battery (or any 12 + volt source that is ALWAYS powered). This allows the radio clock to keep time and maintain the radio station presets when the vehicle is off / key is removed.
The ACCESSORY wire is connected to a point in the vehicle's electrical system that has 12 volts + whenever the ignition key is turned to the Run or Acessory position. When the key is NOT in these positions, the point should go from 12 volts + to 0. This change tells the radio to turn on or off, depending on the key position. The radio will power down when the key is removed, so you do not need to manually shut the radio off. This can save the battery if the radio volume was very low. The ONLY time you would accept both of these wires to be connected to the same point is when they are BOTH connected to the 12 volt + terminal of a battery (or wire that is always powered). If you wire this way, you will have to tune the power on and off each time you want to listen to the radio.
Check you manual for color or lable of these two wires, and place them as needed for the desired operation 1) Both on a constant 12 volt + source, or 2) BATT to a constant 12 volt + source and ACC to switched 12 volt + source.
I hope this helps. Please rate my reply with "4 thumbs up" if it did. Thanks!
Usually, purchase of a wiring harness designed specifically for your vehicle model and stereo solves this problem - as the required voltages and signals - including speakers - are made up and it is simply a "plug and play" operation. Newer cars will often require a "magic box" if you will, that uses some data signals in the car to turn on and off voltages for the stereo. Not installing the "magic box" will prevent much of the radio from working and can cause the loss of chimes, etc.
If your vehicle doesn't require the magic box
on Aug 01, 2011