Is there a tool/meter that will allow you to touch it to wires in bundles/harnesses to detect power? Ie I have some harnesses wires in the middle of a run that I want to tap to put a power receptacle in. I want to figure out what wires are hot with key in ignition and if the power goes off when key is taken out. I know you can use a meter if you have a access to the ends. I don't want to cut into the wires. A/c has a cool little tool that you can touch it to see if a wire is hot. I was told that car voltage is so low its hard to detect. One guy told me I could get a "neon light" detector. He said neon light uses low voltage. I asked 3 auto stores and home depot and no one knows what I'm talking about. Any help?