Product description NWANSI DC 60V 72V to 12V/ 13.8V /19V/24V Power Converter, 5A/10A/15A Product Wiring Instructions The red cable at the input end connects to the positive "+" terminal of the power supply. The black cable at the input end connects to the negative "-" terminal of the power supply. The yellow cable at the output end connects to the positive "+" terminal of the device. The black cable at the output end connects to the negative "-" terminal of the device.