On 5/30/2012 11:36 PM, David Beierl wrote:
> Some people want to use the key-in switch to power the radio, but the
> switch isn't hefty enough to do that reliably. However the switch
> can power a relay that would power the radio.

I haven't seen anyone say to connect the radio power through the "key
in" circuit. I have seen them advise connecting the "ignition sense"
input to the radio there, but that only draws a few milliamps, on all
the car stereos I've ever dealt with. It isn't used to power the radio,
just signal it to turn on. The radio power lead would still go to a
hefty DC source.