Aftermarket Amps With Factory Head Unit

[GRB]

Not sure if anyone has encountered this.. I recently installed three amps and a pair of 10" subs in my 08 Silverado extra cab. The accessory circuit in the newer GM's keeps the radio on until the door is opened, this is not really new. What is interesting is that circuit is only 7.5v and most likely controlled by a module. This circuit doesn't work so well for turning on three amps, you need a good 12v source. I found a 12v accessory circuit in the courtesy panel at the drivers side kick panel to trigger a relay that turns on the amps. The only down side of this is the amps turn off with the ignition instead of when the door is open. I will correct this by using a relay with a 6v coil and wiring it to the accessory circuit.