
Originally Posted by
Holdmybeer
MLA suggestion is not a bad one. Backfiring the 12v to the IGN won't hurt anything but it will power other devices you do not know is running and drain the battery quicker. Having 2 power sources at the same time running from different size fuses/breakers could cause a problem if the radio becomes shorted to ground. The wires designed for 10A radio are now supplied more and wires can melt. Again, being dramatic but things happen and don't want to see anything happen that could be corrected.
Running the yellow radio wire to constant 12v and using the switch to power the red radio wire will work better. I know the switch would have to be on to power the radio and could easily be left on and drain batteries. However, if you turn the batter switch off regularly then this a moot point also.