Re: Hardwiring stereo
What does the yellow wire do?
I'm in the market for a new radio, so just collecting data at this point.
BTW, my current radio is hardwired and yes it has been left on once before resulting in a mostly dead battery. Now I double check before putting it up.
Other than speaker and input wires, there are three power wires to a modern radio/stereo:
Power to the unit
Power to the memory circuit to maintain preset stations, etc.
Negative
It's been a while since I installed one, but I believe the power wire is normally red, the memory wire is yellow, and the negative wire is black. It will be in the installation instructions so just read and follow them.
The power wire should be connected to a source that's switched off by the battery switch, the memory wire should be connected to a source that's not switched off by the battery switch, and the negative wire should be connected to a negative buss bar or other connection that returns to the battery negative terminal.
edit: There might also be a wire that's used to turn on an external power amplifier.