Checking for 'signal' on the orange wire is not very scientific, that signal is about 150 to 200 volts DC and is meant to be dumped into a load of less than 1Ω. Almost a short. Also worth noting, if you crank the engine without a good path for the secondary of the coil to ground, i.e. through the plug, it can ruin the coil as it will try to jump inside and create a path to ground. Sounds like you may have a bad or incorrect coil.