Will the black wire connected to cig lighter.

It could. The radio has a constant 12 volt circuit to run the radio preset and clock memory circuits. That circuit is always tied in with some other circuit that is always live such as the horn, cigarette lighter, or interior lights. Without that 12 volt memory circuit, some radio models will be dead, some will tune and have a display but will have no sound, and some will work but the clock will go back to 12:00 each time the ignition switch is turned on and the radio presets will go back to factory defaults.