[salazarpf]

I believe all your components HU, line converter, amp, etc. are all in fine working condition. Friends have had parallel situations and I've remedied them. I am pretty sure it is the amplifier. In case you don't get a hold of me; Install everything but don't screw the amplifier down lay in on top of a bath towel or some other garment; this will isolate the amplifier. If the hiss goes away after revving the engine, then you have what is called a ground loop, caused unintentionally when the amplifier is installed. Basically the amplifier chassis is making direct contact with the truck possibly through the screws that held the amplifier to the floor or wall. The screw probably scraped the paint off the amp chassis or the plastic protectors on the screw holes of the amp fell off. Hence the direct contact of the amp to the truck by means of the screw. Don't let the screws touch the amplifier when securing it down. You can simply use elecrical tape on the screw heads or screw holes on the amplifier to avoid the direct contact.