blown fuse with new head unit

I have installed a new clarion head unit and rear view camera in my '05 Honda Pilot.  The head unit and camera to work properly, however when the power is connected to the head unit it blows the fuse for my dash light/tail light.  The fuse blows each time I turn on the headlights.  When I remove the head unit from the wire harness and change the fuse, the lights work just fine.  But as soon as I plug the head unit back in, the fuse blows again.  I don't think there is any effect on my head unit.  I have not tapped into any wires other than the reverse light to trigger the camera to work.  What could possibly being causing my fuse to blow?  Would appreciate any suggestions? 

Sounds like a short? Where is the fuse? on your radio harness? Are your wires exposed? This happened to me, I had headunit ground wire exposed and it blew the fuse for my gauges/dome light.Soldier: This is the worst part. The calm before the battle.

Fry: And then the battle is not so bad?

Soldier: Oh, right. I forgot about the battle.

You grounded the radio to the Illumination wire of the vehicle.  When the lights are off, that wire checks as a ground, when you turn the lights on it now has 12 volts on it.  Cut the ground wire of your radio off of whatefer wire you had it connected to, and ground the radio to the chassis of the vehicle. I am offering a triple your money back guarantee on this one.