OK, changed my radio a few months ago, and the same thing happened to me. Looked high and low thru wiring diagrams, schmatics, and otherthings way over my paygrade to no avail. I mean I spent the better part of 2 days. Went back to basics and just started inspecting fuses. And wouldn't u know it, it was one of those tiny jobbies in the fuse box under the hood, 20 amp i think. Check that little f%$ker, can't remember the exact position or the exact amps, but to check all of them will take only a few minutes.