Certified electrician? Is he working on your house or your car?
I would imagine if an electrician can spell DC he's passed that half of the test.
Hopefully someone will jump in and set me straight, but I'm not sure a certified electrician carries any weight in AUTOLAND.
I would have him unhook the battery, undo everything electrical up to this point, return to original and hook the battery back up. Hopefully, you'll be back to square one.