2010 Sequoia keeps blowing radio fuse

My 2010 Sequoia keeps blowing the 7.5 amp radio/nav/backup light fuse. Its random and happens even if the stereo is off. I looked for loose or bare wires in my back hatch to see if it was an issue with the backup camera, but found nothing. It happens at vehicle start and has been happening more frequently. Anyone have a similar issue and have advice?

 

Aftermarket radio or factory?
You definitely got a short somewhere rubbing wire(s).

 

I had a phone charger plugged in to the accessory jack and a USB plugged in to the input. I've unplugged them both and so far no blown fuses. Somehow I doubt that is the cause, but keeping my fingers crossed.

 

It would seems weird that both of those would cause it. Unless the phone charger is pulling way too much power causing the fuse to pop.