How do you turn auxiliary source 1 on for Pioneer DEH-P400UB car radio?

Question

Please don't quote the manual, its no help.

Answer 1

push the source button :)

Answer 2

if the source button doesn't find the Aux input, turn the radio off (the display should still be on), hit Function until you find the Aux 1, it sill say On or Off, if it's off hit the "next" button (usually the right arrow) and it will say On then. Then turn your radio back on,  hit source and the Aux 1 should show up.