Oh I'm sure that Ignition switched is fused somewhere. But I wouldn't have a clue at what rating.

I'm going to redo the basic install The Right Way(tm). I've just bought a Monster 10Ga amp kit to handle permanent power and ground for the HU and empeg. I'll have to hack my sled harness around somewhat to cater for it.... Hmm. I need some 10Ga capable quick connects.

After that I'll look at the GPS again. It was a quick and dirty hack in the first place. I know that there's room for improvement there.