The remote turn on normaly isn't connected into the harness. You should be able to pull the radio out and locate the the remote. Most installers will just tape it off as there is no connection in the harness for it, mine was just taped on the oem stereo.

You could run the wire to somthing conected to your accesories. Or you could always run an 18awg wire right to your battery make sure its fused and have a toggle under your seat.